Download - VMWare Interview Questions
VMWare interview questions
1 What versions of ESX Server you have knowledgemdashESX 40 amp ESXi 40
2 What versions of Virtualcenter server you have knowledge ndash vCenter Server40
3 Roles and responsibilities on VMware mdashTaking care of 3 ESX Servers 66 VMs
amp 1 vCenter Server -= Veeam Monitor 50 versionmdashVDR 12- Managing virtual
infrastructure through vSphere client 40 amp taking care of iSCSI SAN -
4 Explain about your VMware environment No of ESX Servers No of VM in each
ESX Server What features are used How are they connected to storage
5 What is the maximum no of virtual machines can be created on a Single ESX
Server with high end configuration -- Max-320
6 ESX server supports how many processors ndash 512 vCPUs per host
7 ESX server supports what capacity of RAM -- 1 TB
8 How many processors can be allocated to VM ndash 8 vCPU
9 How many NICs can be allocated to VM - 10
10What is the maximum RAM can be allocated to VM 256 GB
11What files are associated with VM ---
12What is Service Console
13What is VMKernal
14How many networks will be installed by default in ESX Server
15Which network is used for storage purpose
16How many virtual switches can be created in ESX Server
17When I try to power on VM it is displaying error message Canrsquot map memory
for VM Cannot allocate memory What are the reasons for the same
a When there is no free space in VMkernal SWAP File on the VMFS file
system Increase the VMkernal SWAP file to atleast physical RAM Size
18How can you check the Physical NICrsquos in service console
19How can you format VMFS file system in Service console
20How to clone a VM in Service console without Virtual Center 1
21What is a cold migrate
22What is a storage vmotion
23What happens to Virtaul Machines when one server in HA cluster goes down
24What happens to Virtual machines when one server in DRS cluster goes down
25Can we establish a cluster with different processor
26Explain technical functionality of Vmotion
27Explain technical functionality of HA Cluster
28In cluster if Virtual center goes down what happens
29What is the port no of Virtual Center server
30Which Webserver will be used by Virtual Center server
31How can you verify the physical Ethernet adaptors using Service console
32What do you mean by Paravirtualization
33How do you create Resource pools
34What is the difference between Limit amp Reservation in Resource pools
35What is the use of Shares
36What is difference between available memory and Reservation
37What is role as a Vmware administrator
38What kind of activities will be performed on a daily basis in ESX Server
39Explain about your environment ( How many esx servers configuration of esx
servers how many virtual machines storage)
40How do extent datastores
41Can we attach 4 TB Partition as VMFS filesystem
42What is the use of promiscuous mode in Traffic shaping
43What traffic shaping policies are available
44Which daemon in ESX server is responsible for authenticating
45Which daemon in ESX Server is responsible for responding to Virtual Center
46What is the maximum no of ESX Servers can be added to Virtual center 2
47What happens to virtual center if you change the password of root account in ESX Server
48What will you do if OS Gets corrupted in VM
49How do you troubleshoot the Guest Os in VM
50How do you troubleshoot ESX Server
51How do you power on VM in Service console
52Where do you configure SMTP Server
53What is the default traffic routing settings
54What is the recent Patch name amp number released by VMware for ESX Server
and Virtual Center
55What is VCB amp explain technical functionality of VCB
56How do you configure ISCSI storage devices
57How does VLAN amp Port groups differ
58What settings should be done in Physical switch if All VLAN information should
be exposed to ESX Server
59If huge number of Virtual machines to be deployed then how do you do this
60If you want to roll back changes in VM then what will you do
61How do you restore backup of a VM
62How do you verify the version of ESX Server from service console and as well in
VI Client
63How do you get the list of VM running in Service console
64How do you get resource usage information from service console
65Where does the VM log files stored
66Can I use schedule tasks in VI Client connected to ESX host
67What is the difference between volume based migration and disk based
migration
68 how do you configure logical volumes in linux
69 How do you parse commands to Redhat kernel 3
70 What boot modes available in Redhat
71 what tools did u use for p2v
72 What versions of p2v used for migration
73 What do u mean by hot cloning and cold cloning
74 Is it possible to do hot cloning for linux box
75 What errors you faced during p2v take few cases and explain and how did u resolve
76 What steps you will take to resolve kernel panic error in ESX
77 How do you approach to resolve Linux boot problems after migration from physical server
78 How do you resolve blue screen errors after migration from physical server and which case it
throws a blue screen
79 How many servers did you do p2v How did you plan
80 How do you configure NTP settings amp how do you verify it is working fine or not
81How to list the patches installed in ESX Server
82 Which command is used to check the ESX updates and install
83 What are the disadvantages of Vmotion
84 Compare Hyper-v with ESX Server
85 How do you stop migration of VM to different esx server in DRS Cluster
Q1) Are we able to add odd number virtual CPUs to our virtual machines for example 3 or 5 VCPU as
compared to VI3 version when virtual SMP only supports 2 or 4 VCPU per virtual machine
Yes we can now add odd number VCPU to our virtual machines
4
Q2) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q3) What is the disadvantage of configuring VM direct path IO for a virtual machine
If we configured VM direct path IO the virtual machine gains significant performance improvement as it is provided
direct access through the adapter however it loses its virtualization features and the adapter cannot be used by other
virtual machines
Q4) Does vSphere provide support for the currently version of VMware Site Recovery Manage version
10
vSphere has does not support SRM version 10 at this present moment
Q5) What is the benefit of using a Distributed vSwitch as compared to a Standard vSwitch
With a distributed virtual switch the network statistics and policies of the virtual machine that has been vmotion to
another ESX Server will migrate with the VM This provides the ability for network vmotion and is useful for
implementing inline intrusion detection systems and firewalls
Q6) Does ESX 4 and ESXi 4 support jumbo frames and TSO
Yes both ESX 4 and ESXi 4 provides support for jumbo frames as well as TSO these can now be configured in the
GUI as compared to VI3 where administrators could only do it via command lines
Q7) What is the different between VMware Data Protection as compared to the traditional VMware
Consolidated Backup
VMware Data Protection supports all storage architecture for backup and restore via LAN and SAN It also supports
full incremental and differential file level backup options
Q8) What is the key driving factor for users adopting VMware vCenter Data Recovery
Its an API that runs in a virtual machine within your vCenter it provides agentless backup and can backup virtual
machines even when they are being vmotion to a different host
Q9) Can we perform Storage Vmotion now via the GUI inside vCenter
Yes Storage Vmotion feature is now avaliable in the vSphere Client connected to vCenter Server It provides full
support for FC SAN and NFS
Q10) When using vCenter Linked Mode feature what are the functions that could be shared among the
vCenters in this link
vCenter Linked Mode allows administrator to centrally manage all the vCenter within a single view roles and licenses
can be shared across the vCenters configured in a link
Q11) Do I still require a Flexnet License Server if all my ESX Servers are ESX 4 and ESXi 4
No you no longer require a license server for the to manage the new ESX Servers All licenses are managed within the
vCenter Server
5
Q12) If my customer has a hybrid environment where they still have ESX 3 and ESX 35 can vCenter
communicate with the existing Flexnet License Server
Yes vCenter can communicate with existing license servers so as to allow it to manage legacy ESX Servers vCenter
will pull the licenses for legacy hosts from the flexnet license server
Q13) Why am I unable to hot add CPU and memory to virtual machine
You are required to enable this function under the virtual machine settings in order to use it Therefore it is advisable
to enable it before you start your virtual machine for the very first time
Q14) Is it true we can now use the new VMware Update Manager to upgrade our legacy ESX Servers
(For example ESX 35) to ESX 40 version
Yes the new VUM has the ability to upgrade your legacy ESX Server hosts for you However if you are upgrading a
standalone host you will be required to power off all virtual machines running on that host
Q15) How come we are unable to use our existing VI Client to manage our ESX 4 and vCenter 4
No the legacy VI Client is unable to manage newer ESX Server Hosts and vCenter You will need to install vSphere
Client to manage newer ESX Server Hosts and vCenter as well as legacy ESX Hosts
Q16) In vSphere can we configure bidirectional CHAP authentication for iSCSI
Yes we can now configure bidirectional CHAP authenticaton for iSCSI software It is fully supported Previously we
could only configure unidirectional CHAP authentication
Q17) Do we still need to configure a Service Console port for iSCSI initiator
No we no longer need a Service Console for software iSCSI initator The vmkiscsid no longer runs in the Service
Console There have been improvements made to the new iSCSI stack in the kernel and also with the use of TCPIP2
which has multi threading capabilities
Q18) What is the maximum number of CPU and maximum amount of memory a virtual machine can
scale
In vSphere a virtual machine can now be configure with a maximum of 8 virtual CPUs and 255 GB of memory
Q19) What is the maximum amount of logical CPUs and memory per ESX Server 4 host can scale
ESX Server 4 now supports a maximum of 64 logical CPUs and 1 TB of memory
Q20) What actions allow us to configure thin disk provisioning for a virtual machine
When we create a new virtual machine clone an existing virtual machine clone a template or perform Storage
Vmotion on an existing virtual machine
Q21) What is the benefit of configuring thin disk provisioning as compared to thick disk provisioning
for a virtual machine
When we configure thin disk provisioning the virtual machine only uses the space that it requires and not the entire
disk size this allows the remaining unused space for other virtual machines This enables us to do Storage Overcommitment
and use the storage more efficiently
6
Q22) Will my virtual machines still have connection if the virtual center that stores my Distributed
vSwitch configuration goes down
Yes this is because the Distributed vSwitch has an control plane which sits at the vCenter Server level and an IO
plane which are the form of hidden vSwitches sitting at the ESX level Therefore even if the vCenter goes down
virtual machines continue to have connectivity through the IO plane at the ESX level
Q23) What is the maximum number of ESX Hosts we can connect to a single distributed switch
We can connect up to 64 ESX hosts per distributed switch and vCenter 4 can support up a maximum of 16 distributed
switches Which means we can have up to 1024 hosts on these 16 distributed switches Refer to Configure
Maximums for more details
Q24) What is the version of the 64 bit Service Console running in ESX 4
The Service Console is a 26 linux kernel compatible with Red Hat Enterprise Linux 52 or CentOS 52 version
Q25) What is the maximum number of uplinks or ports per ESX 4 or ESXi 4 Host
The maximum number of uplinks per ESX 4 or ESXi 4 Host is 32 uplinks Refer to Configure Maximums for more
details
Q26) Can we install vCenter Server on a 64 bit Windows OS
Yes vCenter Server can be installed on both 32-bit and 64-bit Windows OS Refer to Compatibility matrix for more
details
Q27) Does ESXESXi 4 supports round robin multipathing policy
Yes besides fixed (preferred) and most recently used (MRU) ESXESXi 4 now supports round robin multipathing
policy and it has to be configured on the storage level
Q28) Can vCenter 4 support a cluster which includes ESX 3x and ESX 4 hosts
Yes we can cluster legacy ESX 3x hosts and ESX 4 hosts together in the same cluster vCenter will have to connect to
the flexnet license server to manage the licenses for the legacy hosts However new features such as hot add and PCI
pass through may not be avaliable to the VMs on legacy hosts Refer to Upgrade Guide for more details
Q29) When upgrading from virtual center 2x to vCenter 4 is there downtime for the host and do we
need to re add the ESX hosts back into the inventory
No theres no time for the hosts and existing hosts will remain in the inventory However there will be downtime for
virtual center Remember to backup the databases as during the upgrade process the database schemas are changed
and in the event of a upgrade failure you will not be able to roll back and you will have to do a restore Refer to
Upgrade Guide for more details
Q30) When we hot add memory to a powered on VM will the swap file get dynamically increased
When we hot add memory to a powered on VM the swap file size will get dynamically increase
Q31) When we hot add memory to a powered on VM and the swap file get dynamically increased what
happens if there is not enough disk space to meet the growing vswap file size
7
You will not be able to add memory to that VM that has not enough memory for the swap file to grow and you will
receive an error
Q32) Can we add USB controllers to our VM in ESXESXi 4
Yes we now have the ability to hot plug USB controller into our VMs while they are running However the usb device
has to be connected to the ESX Server and not the client local machine
Q33) When installing convertor plug-in I get a 404 error and the installation halts
During installation of vCenter Convertor you will have to enter the FQDN instead of the IP address or netbios name as
this may cause you to receive the 404 error when installing the vCenter convertor plug-in later
Q34) Where is Distributed Power Management configured and what are the protocols it uses
DPM is configured and managed at the DRS cluster level It uses IPMI ILO and Wake On LAN protocols DRS can
use DPM to put under utilized hosts into standby modes to save power consumption
Q35) What is new with vCenter 4 user access and role management as compared to the virtual center
25
vCenter 4 allows us the ability to assign administrators to inventory objects such as networks and datastores which
were not available with the previous virtual center version
Q36) What are the new tasks we can schedule in vCenter 4 task scheduler
vCenter 4 task scheduler allows us the ability to schedule a task to increase the resources in a resource pool or
virtual machine This would be good to cater to the needs of virtual machines that will require additional ad-hoc
resources such as finance department doing month end closing which may result in resources surge on their
machines
Q37) How does VMware HA on an ESXi Server sends out heart beat if ESXi does not have a service
console
VMware HA clusters configured for ESXi Servers uses the vmkernel present on all ESXi Servers to send and receive
heart beats Whereas on ESX Servers the heartbeat is send and receive through the service console Therefore we
may not want to cluster ESX and ESXi Servers together in the same cluster
Q38) Can we create a cluster with ESX and ESXi Servers
Yes However VMware HA may not work as both servers uses different port groups to send out heart beats Vmotion
and DRS may still work This is not a supported practise
Q39) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q40) How can I grow an existing VMFS LUN without creating an extent or physical partition
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
3 of 10 232012 713 AM
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
4 of 10 232012 713 AM
9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
23What happens to Virtaul Machines when one server in HA cluster goes down
24What happens to Virtual machines when one server in DRS cluster goes down
25Can we establish a cluster with different processor
26Explain technical functionality of Vmotion
27Explain technical functionality of HA Cluster
28In cluster if Virtual center goes down what happens
29What is the port no of Virtual Center server
30Which Webserver will be used by Virtual Center server
31How can you verify the physical Ethernet adaptors using Service console
32What do you mean by Paravirtualization
33How do you create Resource pools
34What is the difference between Limit amp Reservation in Resource pools
35What is the use of Shares
36What is difference between available memory and Reservation
37What is role as a Vmware administrator
38What kind of activities will be performed on a daily basis in ESX Server
39Explain about your environment ( How many esx servers configuration of esx
servers how many virtual machines storage)
40How do extent datastores
41Can we attach 4 TB Partition as VMFS filesystem
42What is the use of promiscuous mode in Traffic shaping
43What traffic shaping policies are available
44Which daemon in ESX server is responsible for authenticating
45Which daemon in ESX Server is responsible for responding to Virtual Center
46What is the maximum no of ESX Servers can be added to Virtual center 2
47What happens to virtual center if you change the password of root account in ESX Server
48What will you do if OS Gets corrupted in VM
49How do you troubleshoot the Guest Os in VM
50How do you troubleshoot ESX Server
51How do you power on VM in Service console
52Where do you configure SMTP Server
53What is the default traffic routing settings
54What is the recent Patch name amp number released by VMware for ESX Server
and Virtual Center
55What is VCB amp explain technical functionality of VCB
56How do you configure ISCSI storage devices
57How does VLAN amp Port groups differ
58What settings should be done in Physical switch if All VLAN information should
be exposed to ESX Server
59If huge number of Virtual machines to be deployed then how do you do this
60If you want to roll back changes in VM then what will you do
61How do you restore backup of a VM
62How do you verify the version of ESX Server from service console and as well in
VI Client
63How do you get the list of VM running in Service console
64How do you get resource usage information from service console
65Where does the VM log files stored
66Can I use schedule tasks in VI Client connected to ESX host
67What is the difference between volume based migration and disk based
migration
68 how do you configure logical volumes in linux
69 How do you parse commands to Redhat kernel 3
70 What boot modes available in Redhat
71 what tools did u use for p2v
72 What versions of p2v used for migration
73 What do u mean by hot cloning and cold cloning
74 Is it possible to do hot cloning for linux box
75 What errors you faced during p2v take few cases and explain and how did u resolve
76 What steps you will take to resolve kernel panic error in ESX
77 How do you approach to resolve Linux boot problems after migration from physical server
78 How do you resolve blue screen errors after migration from physical server and which case it
throws a blue screen
79 How many servers did you do p2v How did you plan
80 How do you configure NTP settings amp how do you verify it is working fine or not
81How to list the patches installed in ESX Server
82 Which command is used to check the ESX updates and install
83 What are the disadvantages of Vmotion
84 Compare Hyper-v with ESX Server
85 How do you stop migration of VM to different esx server in DRS Cluster
Q1) Are we able to add odd number virtual CPUs to our virtual machines for example 3 or 5 VCPU as
compared to VI3 version when virtual SMP only supports 2 or 4 VCPU per virtual machine
Yes we can now add odd number VCPU to our virtual machines
4
Q2) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q3) What is the disadvantage of configuring VM direct path IO for a virtual machine
If we configured VM direct path IO the virtual machine gains significant performance improvement as it is provided
direct access through the adapter however it loses its virtualization features and the adapter cannot be used by other
virtual machines
Q4) Does vSphere provide support for the currently version of VMware Site Recovery Manage version
10
vSphere has does not support SRM version 10 at this present moment
Q5) What is the benefit of using a Distributed vSwitch as compared to a Standard vSwitch
With a distributed virtual switch the network statistics and policies of the virtual machine that has been vmotion to
another ESX Server will migrate with the VM This provides the ability for network vmotion and is useful for
implementing inline intrusion detection systems and firewalls
Q6) Does ESX 4 and ESXi 4 support jumbo frames and TSO
Yes both ESX 4 and ESXi 4 provides support for jumbo frames as well as TSO these can now be configured in the
GUI as compared to VI3 where administrators could only do it via command lines
Q7) What is the different between VMware Data Protection as compared to the traditional VMware
Consolidated Backup
VMware Data Protection supports all storage architecture for backup and restore via LAN and SAN It also supports
full incremental and differential file level backup options
Q8) What is the key driving factor for users adopting VMware vCenter Data Recovery
Its an API that runs in a virtual machine within your vCenter it provides agentless backup and can backup virtual
machines even when they are being vmotion to a different host
Q9) Can we perform Storage Vmotion now via the GUI inside vCenter
Yes Storage Vmotion feature is now avaliable in the vSphere Client connected to vCenter Server It provides full
support for FC SAN and NFS
Q10) When using vCenter Linked Mode feature what are the functions that could be shared among the
vCenters in this link
vCenter Linked Mode allows administrator to centrally manage all the vCenter within a single view roles and licenses
can be shared across the vCenters configured in a link
Q11) Do I still require a Flexnet License Server if all my ESX Servers are ESX 4 and ESXi 4
No you no longer require a license server for the to manage the new ESX Servers All licenses are managed within the
vCenter Server
5
Q12) If my customer has a hybrid environment where they still have ESX 3 and ESX 35 can vCenter
communicate with the existing Flexnet License Server
Yes vCenter can communicate with existing license servers so as to allow it to manage legacy ESX Servers vCenter
will pull the licenses for legacy hosts from the flexnet license server
Q13) Why am I unable to hot add CPU and memory to virtual machine
You are required to enable this function under the virtual machine settings in order to use it Therefore it is advisable
to enable it before you start your virtual machine for the very first time
Q14) Is it true we can now use the new VMware Update Manager to upgrade our legacy ESX Servers
(For example ESX 35) to ESX 40 version
Yes the new VUM has the ability to upgrade your legacy ESX Server hosts for you However if you are upgrading a
standalone host you will be required to power off all virtual machines running on that host
Q15) How come we are unable to use our existing VI Client to manage our ESX 4 and vCenter 4
No the legacy VI Client is unable to manage newer ESX Server Hosts and vCenter You will need to install vSphere
Client to manage newer ESX Server Hosts and vCenter as well as legacy ESX Hosts
Q16) In vSphere can we configure bidirectional CHAP authentication for iSCSI
Yes we can now configure bidirectional CHAP authenticaton for iSCSI software It is fully supported Previously we
could only configure unidirectional CHAP authentication
Q17) Do we still need to configure a Service Console port for iSCSI initiator
No we no longer need a Service Console for software iSCSI initator The vmkiscsid no longer runs in the Service
Console There have been improvements made to the new iSCSI stack in the kernel and also with the use of TCPIP2
which has multi threading capabilities
Q18) What is the maximum number of CPU and maximum amount of memory a virtual machine can
scale
In vSphere a virtual machine can now be configure with a maximum of 8 virtual CPUs and 255 GB of memory
Q19) What is the maximum amount of logical CPUs and memory per ESX Server 4 host can scale
ESX Server 4 now supports a maximum of 64 logical CPUs and 1 TB of memory
Q20) What actions allow us to configure thin disk provisioning for a virtual machine
When we create a new virtual machine clone an existing virtual machine clone a template or perform Storage
Vmotion on an existing virtual machine
Q21) What is the benefit of configuring thin disk provisioning as compared to thick disk provisioning
for a virtual machine
When we configure thin disk provisioning the virtual machine only uses the space that it requires and not the entire
disk size this allows the remaining unused space for other virtual machines This enables us to do Storage Overcommitment
and use the storage more efficiently
6
Q22) Will my virtual machines still have connection if the virtual center that stores my Distributed
vSwitch configuration goes down
Yes this is because the Distributed vSwitch has an control plane which sits at the vCenter Server level and an IO
plane which are the form of hidden vSwitches sitting at the ESX level Therefore even if the vCenter goes down
virtual machines continue to have connectivity through the IO plane at the ESX level
Q23) What is the maximum number of ESX Hosts we can connect to a single distributed switch
We can connect up to 64 ESX hosts per distributed switch and vCenter 4 can support up a maximum of 16 distributed
switches Which means we can have up to 1024 hosts on these 16 distributed switches Refer to Configure
Maximums for more details
Q24) What is the version of the 64 bit Service Console running in ESX 4
The Service Console is a 26 linux kernel compatible with Red Hat Enterprise Linux 52 or CentOS 52 version
Q25) What is the maximum number of uplinks or ports per ESX 4 or ESXi 4 Host
The maximum number of uplinks per ESX 4 or ESXi 4 Host is 32 uplinks Refer to Configure Maximums for more
details
Q26) Can we install vCenter Server on a 64 bit Windows OS
Yes vCenter Server can be installed on both 32-bit and 64-bit Windows OS Refer to Compatibility matrix for more
details
Q27) Does ESXESXi 4 supports round robin multipathing policy
Yes besides fixed (preferred) and most recently used (MRU) ESXESXi 4 now supports round robin multipathing
policy and it has to be configured on the storage level
Q28) Can vCenter 4 support a cluster which includes ESX 3x and ESX 4 hosts
Yes we can cluster legacy ESX 3x hosts and ESX 4 hosts together in the same cluster vCenter will have to connect to
the flexnet license server to manage the licenses for the legacy hosts However new features such as hot add and PCI
pass through may not be avaliable to the VMs on legacy hosts Refer to Upgrade Guide for more details
Q29) When upgrading from virtual center 2x to vCenter 4 is there downtime for the host and do we
need to re add the ESX hosts back into the inventory
No theres no time for the hosts and existing hosts will remain in the inventory However there will be downtime for
virtual center Remember to backup the databases as during the upgrade process the database schemas are changed
and in the event of a upgrade failure you will not be able to roll back and you will have to do a restore Refer to
Upgrade Guide for more details
Q30) When we hot add memory to a powered on VM will the swap file get dynamically increased
When we hot add memory to a powered on VM the swap file size will get dynamically increase
Q31) When we hot add memory to a powered on VM and the swap file get dynamically increased what
happens if there is not enough disk space to meet the growing vswap file size
7
You will not be able to add memory to that VM that has not enough memory for the swap file to grow and you will
receive an error
Q32) Can we add USB controllers to our VM in ESXESXi 4
Yes we now have the ability to hot plug USB controller into our VMs while they are running However the usb device
has to be connected to the ESX Server and not the client local machine
Q33) When installing convertor plug-in I get a 404 error and the installation halts
During installation of vCenter Convertor you will have to enter the FQDN instead of the IP address or netbios name as
this may cause you to receive the 404 error when installing the vCenter convertor plug-in later
Q34) Where is Distributed Power Management configured and what are the protocols it uses
DPM is configured and managed at the DRS cluster level It uses IPMI ILO and Wake On LAN protocols DRS can
use DPM to put under utilized hosts into standby modes to save power consumption
Q35) What is new with vCenter 4 user access and role management as compared to the virtual center
25
vCenter 4 allows us the ability to assign administrators to inventory objects such as networks and datastores which
were not available with the previous virtual center version
Q36) What are the new tasks we can schedule in vCenter 4 task scheduler
vCenter 4 task scheduler allows us the ability to schedule a task to increase the resources in a resource pool or
virtual machine This would be good to cater to the needs of virtual machines that will require additional ad-hoc
resources such as finance department doing month end closing which may result in resources surge on their
machines
Q37) How does VMware HA on an ESXi Server sends out heart beat if ESXi does not have a service
console
VMware HA clusters configured for ESXi Servers uses the vmkernel present on all ESXi Servers to send and receive
heart beats Whereas on ESX Servers the heartbeat is send and receive through the service console Therefore we
may not want to cluster ESX and ESXi Servers together in the same cluster
Q38) Can we create a cluster with ESX and ESXi Servers
Yes However VMware HA may not work as both servers uses different port groups to send out heart beats Vmotion
and DRS may still work This is not a supported practise
Q39) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q40) How can I grow an existing VMFS LUN without creating an extent or physical partition
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
52Where do you configure SMTP Server
53What is the default traffic routing settings
54What is the recent Patch name amp number released by VMware for ESX Server
and Virtual Center
55What is VCB amp explain technical functionality of VCB
56How do you configure ISCSI storage devices
57How does VLAN amp Port groups differ
58What settings should be done in Physical switch if All VLAN information should
be exposed to ESX Server
59If huge number of Virtual machines to be deployed then how do you do this
60If you want to roll back changes in VM then what will you do
61How do you restore backup of a VM
62How do you verify the version of ESX Server from service console and as well in
VI Client
63How do you get the list of VM running in Service console
64How do you get resource usage information from service console
65Where does the VM log files stored
66Can I use schedule tasks in VI Client connected to ESX host
67What is the difference between volume based migration and disk based
migration
68 how do you configure logical volumes in linux
69 How do you parse commands to Redhat kernel 3
70 What boot modes available in Redhat
71 what tools did u use for p2v
72 What versions of p2v used for migration
73 What do u mean by hot cloning and cold cloning
74 Is it possible to do hot cloning for linux box
75 What errors you faced during p2v take few cases and explain and how did u resolve
76 What steps you will take to resolve kernel panic error in ESX
77 How do you approach to resolve Linux boot problems after migration from physical server
78 How do you resolve blue screen errors after migration from physical server and which case it
throws a blue screen
79 How many servers did you do p2v How did you plan
80 How do you configure NTP settings amp how do you verify it is working fine or not
81How to list the patches installed in ESX Server
82 Which command is used to check the ESX updates and install
83 What are the disadvantages of Vmotion
84 Compare Hyper-v with ESX Server
85 How do you stop migration of VM to different esx server in DRS Cluster
Q1) Are we able to add odd number virtual CPUs to our virtual machines for example 3 or 5 VCPU as
compared to VI3 version when virtual SMP only supports 2 or 4 VCPU per virtual machine
Yes we can now add odd number VCPU to our virtual machines
4
Q2) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q3) What is the disadvantage of configuring VM direct path IO for a virtual machine
If we configured VM direct path IO the virtual machine gains significant performance improvement as it is provided
direct access through the adapter however it loses its virtualization features and the adapter cannot be used by other
virtual machines
Q4) Does vSphere provide support for the currently version of VMware Site Recovery Manage version
10
vSphere has does not support SRM version 10 at this present moment
Q5) What is the benefit of using a Distributed vSwitch as compared to a Standard vSwitch
With a distributed virtual switch the network statistics and policies of the virtual machine that has been vmotion to
another ESX Server will migrate with the VM This provides the ability for network vmotion and is useful for
implementing inline intrusion detection systems and firewalls
Q6) Does ESX 4 and ESXi 4 support jumbo frames and TSO
Yes both ESX 4 and ESXi 4 provides support for jumbo frames as well as TSO these can now be configured in the
GUI as compared to VI3 where administrators could only do it via command lines
Q7) What is the different between VMware Data Protection as compared to the traditional VMware
Consolidated Backup
VMware Data Protection supports all storage architecture for backup and restore via LAN and SAN It also supports
full incremental and differential file level backup options
Q8) What is the key driving factor for users adopting VMware vCenter Data Recovery
Its an API that runs in a virtual machine within your vCenter it provides agentless backup and can backup virtual
machines even when they are being vmotion to a different host
Q9) Can we perform Storage Vmotion now via the GUI inside vCenter
Yes Storage Vmotion feature is now avaliable in the vSphere Client connected to vCenter Server It provides full
support for FC SAN and NFS
Q10) When using vCenter Linked Mode feature what are the functions that could be shared among the
vCenters in this link
vCenter Linked Mode allows administrator to centrally manage all the vCenter within a single view roles and licenses
can be shared across the vCenters configured in a link
Q11) Do I still require a Flexnet License Server if all my ESX Servers are ESX 4 and ESXi 4
No you no longer require a license server for the to manage the new ESX Servers All licenses are managed within the
vCenter Server
5
Q12) If my customer has a hybrid environment where they still have ESX 3 and ESX 35 can vCenter
communicate with the existing Flexnet License Server
Yes vCenter can communicate with existing license servers so as to allow it to manage legacy ESX Servers vCenter
will pull the licenses for legacy hosts from the flexnet license server
Q13) Why am I unable to hot add CPU and memory to virtual machine
You are required to enable this function under the virtual machine settings in order to use it Therefore it is advisable
to enable it before you start your virtual machine for the very first time
Q14) Is it true we can now use the new VMware Update Manager to upgrade our legacy ESX Servers
(For example ESX 35) to ESX 40 version
Yes the new VUM has the ability to upgrade your legacy ESX Server hosts for you However if you are upgrading a
standalone host you will be required to power off all virtual machines running on that host
Q15) How come we are unable to use our existing VI Client to manage our ESX 4 and vCenter 4
No the legacy VI Client is unable to manage newer ESX Server Hosts and vCenter You will need to install vSphere
Client to manage newer ESX Server Hosts and vCenter as well as legacy ESX Hosts
Q16) In vSphere can we configure bidirectional CHAP authentication for iSCSI
Yes we can now configure bidirectional CHAP authenticaton for iSCSI software It is fully supported Previously we
could only configure unidirectional CHAP authentication
Q17) Do we still need to configure a Service Console port for iSCSI initiator
No we no longer need a Service Console for software iSCSI initator The vmkiscsid no longer runs in the Service
Console There have been improvements made to the new iSCSI stack in the kernel and also with the use of TCPIP2
which has multi threading capabilities
Q18) What is the maximum number of CPU and maximum amount of memory a virtual machine can
scale
In vSphere a virtual machine can now be configure with a maximum of 8 virtual CPUs and 255 GB of memory
Q19) What is the maximum amount of logical CPUs and memory per ESX Server 4 host can scale
ESX Server 4 now supports a maximum of 64 logical CPUs and 1 TB of memory
Q20) What actions allow us to configure thin disk provisioning for a virtual machine
When we create a new virtual machine clone an existing virtual machine clone a template or perform Storage
Vmotion on an existing virtual machine
Q21) What is the benefit of configuring thin disk provisioning as compared to thick disk provisioning
for a virtual machine
When we configure thin disk provisioning the virtual machine only uses the space that it requires and not the entire
disk size this allows the remaining unused space for other virtual machines This enables us to do Storage Overcommitment
and use the storage more efficiently
6
Q22) Will my virtual machines still have connection if the virtual center that stores my Distributed
vSwitch configuration goes down
Yes this is because the Distributed vSwitch has an control plane which sits at the vCenter Server level and an IO
plane which are the form of hidden vSwitches sitting at the ESX level Therefore even if the vCenter goes down
virtual machines continue to have connectivity through the IO plane at the ESX level
Q23) What is the maximum number of ESX Hosts we can connect to a single distributed switch
We can connect up to 64 ESX hosts per distributed switch and vCenter 4 can support up a maximum of 16 distributed
switches Which means we can have up to 1024 hosts on these 16 distributed switches Refer to Configure
Maximums for more details
Q24) What is the version of the 64 bit Service Console running in ESX 4
The Service Console is a 26 linux kernel compatible with Red Hat Enterprise Linux 52 or CentOS 52 version
Q25) What is the maximum number of uplinks or ports per ESX 4 or ESXi 4 Host
The maximum number of uplinks per ESX 4 or ESXi 4 Host is 32 uplinks Refer to Configure Maximums for more
details
Q26) Can we install vCenter Server on a 64 bit Windows OS
Yes vCenter Server can be installed on both 32-bit and 64-bit Windows OS Refer to Compatibility matrix for more
details
Q27) Does ESXESXi 4 supports round robin multipathing policy
Yes besides fixed (preferred) and most recently used (MRU) ESXESXi 4 now supports round robin multipathing
policy and it has to be configured on the storage level
Q28) Can vCenter 4 support a cluster which includes ESX 3x and ESX 4 hosts
Yes we can cluster legacy ESX 3x hosts and ESX 4 hosts together in the same cluster vCenter will have to connect to
the flexnet license server to manage the licenses for the legacy hosts However new features such as hot add and PCI
pass through may not be avaliable to the VMs on legacy hosts Refer to Upgrade Guide for more details
Q29) When upgrading from virtual center 2x to vCenter 4 is there downtime for the host and do we
need to re add the ESX hosts back into the inventory
No theres no time for the hosts and existing hosts will remain in the inventory However there will be downtime for
virtual center Remember to backup the databases as during the upgrade process the database schemas are changed
and in the event of a upgrade failure you will not be able to roll back and you will have to do a restore Refer to
Upgrade Guide for more details
Q30) When we hot add memory to a powered on VM will the swap file get dynamically increased
When we hot add memory to a powered on VM the swap file size will get dynamically increase
Q31) When we hot add memory to a powered on VM and the swap file get dynamically increased what
happens if there is not enough disk space to meet the growing vswap file size
7
You will not be able to add memory to that VM that has not enough memory for the swap file to grow and you will
receive an error
Q32) Can we add USB controllers to our VM in ESXESXi 4
Yes we now have the ability to hot plug USB controller into our VMs while they are running However the usb device
has to be connected to the ESX Server and not the client local machine
Q33) When installing convertor plug-in I get a 404 error and the installation halts
During installation of vCenter Convertor you will have to enter the FQDN instead of the IP address or netbios name as
this may cause you to receive the 404 error when installing the vCenter convertor plug-in later
Q34) Where is Distributed Power Management configured and what are the protocols it uses
DPM is configured and managed at the DRS cluster level It uses IPMI ILO and Wake On LAN protocols DRS can
use DPM to put under utilized hosts into standby modes to save power consumption
Q35) What is new with vCenter 4 user access and role management as compared to the virtual center
25
vCenter 4 allows us the ability to assign administrators to inventory objects such as networks and datastores which
were not available with the previous virtual center version
Q36) What are the new tasks we can schedule in vCenter 4 task scheduler
vCenter 4 task scheduler allows us the ability to schedule a task to increase the resources in a resource pool or
virtual machine This would be good to cater to the needs of virtual machines that will require additional ad-hoc
resources such as finance department doing month end closing which may result in resources surge on their
machines
Q37) How does VMware HA on an ESXi Server sends out heart beat if ESXi does not have a service
console
VMware HA clusters configured for ESXi Servers uses the vmkernel present on all ESXi Servers to send and receive
heart beats Whereas on ESX Servers the heartbeat is send and receive through the service console Therefore we
may not want to cluster ESX and ESXi Servers together in the same cluster
Q38) Can we create a cluster with ESX and ESXi Servers
Yes However VMware HA may not work as both servers uses different port groups to send out heart beats Vmotion
and DRS may still work This is not a supported practise
Q39) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q40) How can I grow an existing VMFS LUN without creating an extent or physical partition
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
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Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
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no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
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VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
78 How do you resolve blue screen errors after migration from physical server and which case it
throws a blue screen
79 How many servers did you do p2v How did you plan
80 How do you configure NTP settings amp how do you verify it is working fine or not
81How to list the patches installed in ESX Server
82 Which command is used to check the ESX updates and install
83 What are the disadvantages of Vmotion
84 Compare Hyper-v with ESX Server
85 How do you stop migration of VM to different esx server in DRS Cluster
Q1) Are we able to add odd number virtual CPUs to our virtual machines for example 3 or 5 VCPU as
compared to VI3 version when virtual SMP only supports 2 or 4 VCPU per virtual machine
Yes we can now add odd number VCPU to our virtual machines
4
Q2) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q3) What is the disadvantage of configuring VM direct path IO for a virtual machine
If we configured VM direct path IO the virtual machine gains significant performance improvement as it is provided
direct access through the adapter however it loses its virtualization features and the adapter cannot be used by other
virtual machines
Q4) Does vSphere provide support for the currently version of VMware Site Recovery Manage version
10
vSphere has does not support SRM version 10 at this present moment
Q5) What is the benefit of using a Distributed vSwitch as compared to a Standard vSwitch
With a distributed virtual switch the network statistics and policies of the virtual machine that has been vmotion to
another ESX Server will migrate with the VM This provides the ability for network vmotion and is useful for
implementing inline intrusion detection systems and firewalls
Q6) Does ESX 4 and ESXi 4 support jumbo frames and TSO
Yes both ESX 4 and ESXi 4 provides support for jumbo frames as well as TSO these can now be configured in the
GUI as compared to VI3 where administrators could only do it via command lines
Q7) What is the different between VMware Data Protection as compared to the traditional VMware
Consolidated Backup
VMware Data Protection supports all storage architecture for backup and restore via LAN and SAN It also supports
full incremental and differential file level backup options
Q8) What is the key driving factor for users adopting VMware vCenter Data Recovery
Its an API that runs in a virtual machine within your vCenter it provides agentless backup and can backup virtual
machines even when they are being vmotion to a different host
Q9) Can we perform Storage Vmotion now via the GUI inside vCenter
Yes Storage Vmotion feature is now avaliable in the vSphere Client connected to vCenter Server It provides full
support for FC SAN and NFS
Q10) When using vCenter Linked Mode feature what are the functions that could be shared among the
vCenters in this link
vCenter Linked Mode allows administrator to centrally manage all the vCenter within a single view roles and licenses
can be shared across the vCenters configured in a link
Q11) Do I still require a Flexnet License Server if all my ESX Servers are ESX 4 and ESXi 4
No you no longer require a license server for the to manage the new ESX Servers All licenses are managed within the
vCenter Server
5
Q12) If my customer has a hybrid environment where they still have ESX 3 and ESX 35 can vCenter
communicate with the existing Flexnet License Server
Yes vCenter can communicate with existing license servers so as to allow it to manage legacy ESX Servers vCenter
will pull the licenses for legacy hosts from the flexnet license server
Q13) Why am I unable to hot add CPU and memory to virtual machine
You are required to enable this function under the virtual machine settings in order to use it Therefore it is advisable
to enable it before you start your virtual machine for the very first time
Q14) Is it true we can now use the new VMware Update Manager to upgrade our legacy ESX Servers
(For example ESX 35) to ESX 40 version
Yes the new VUM has the ability to upgrade your legacy ESX Server hosts for you However if you are upgrading a
standalone host you will be required to power off all virtual machines running on that host
Q15) How come we are unable to use our existing VI Client to manage our ESX 4 and vCenter 4
No the legacy VI Client is unable to manage newer ESX Server Hosts and vCenter You will need to install vSphere
Client to manage newer ESX Server Hosts and vCenter as well as legacy ESX Hosts
Q16) In vSphere can we configure bidirectional CHAP authentication for iSCSI
Yes we can now configure bidirectional CHAP authenticaton for iSCSI software It is fully supported Previously we
could only configure unidirectional CHAP authentication
Q17) Do we still need to configure a Service Console port for iSCSI initiator
No we no longer need a Service Console for software iSCSI initator The vmkiscsid no longer runs in the Service
Console There have been improvements made to the new iSCSI stack in the kernel and also with the use of TCPIP2
which has multi threading capabilities
Q18) What is the maximum number of CPU and maximum amount of memory a virtual machine can
scale
In vSphere a virtual machine can now be configure with a maximum of 8 virtual CPUs and 255 GB of memory
Q19) What is the maximum amount of logical CPUs and memory per ESX Server 4 host can scale
ESX Server 4 now supports a maximum of 64 logical CPUs and 1 TB of memory
Q20) What actions allow us to configure thin disk provisioning for a virtual machine
When we create a new virtual machine clone an existing virtual machine clone a template or perform Storage
Vmotion on an existing virtual machine
Q21) What is the benefit of configuring thin disk provisioning as compared to thick disk provisioning
for a virtual machine
When we configure thin disk provisioning the virtual machine only uses the space that it requires and not the entire
disk size this allows the remaining unused space for other virtual machines This enables us to do Storage Overcommitment
and use the storage more efficiently
6
Q22) Will my virtual machines still have connection if the virtual center that stores my Distributed
vSwitch configuration goes down
Yes this is because the Distributed vSwitch has an control plane which sits at the vCenter Server level and an IO
plane which are the form of hidden vSwitches sitting at the ESX level Therefore even if the vCenter goes down
virtual machines continue to have connectivity through the IO plane at the ESX level
Q23) What is the maximum number of ESX Hosts we can connect to a single distributed switch
We can connect up to 64 ESX hosts per distributed switch and vCenter 4 can support up a maximum of 16 distributed
switches Which means we can have up to 1024 hosts on these 16 distributed switches Refer to Configure
Maximums for more details
Q24) What is the version of the 64 bit Service Console running in ESX 4
The Service Console is a 26 linux kernel compatible with Red Hat Enterprise Linux 52 or CentOS 52 version
Q25) What is the maximum number of uplinks or ports per ESX 4 or ESXi 4 Host
The maximum number of uplinks per ESX 4 or ESXi 4 Host is 32 uplinks Refer to Configure Maximums for more
details
Q26) Can we install vCenter Server on a 64 bit Windows OS
Yes vCenter Server can be installed on both 32-bit and 64-bit Windows OS Refer to Compatibility matrix for more
details
Q27) Does ESXESXi 4 supports round robin multipathing policy
Yes besides fixed (preferred) and most recently used (MRU) ESXESXi 4 now supports round robin multipathing
policy and it has to be configured on the storage level
Q28) Can vCenter 4 support a cluster which includes ESX 3x and ESX 4 hosts
Yes we can cluster legacy ESX 3x hosts and ESX 4 hosts together in the same cluster vCenter will have to connect to
the flexnet license server to manage the licenses for the legacy hosts However new features such as hot add and PCI
pass through may not be avaliable to the VMs on legacy hosts Refer to Upgrade Guide for more details
Q29) When upgrading from virtual center 2x to vCenter 4 is there downtime for the host and do we
need to re add the ESX hosts back into the inventory
No theres no time for the hosts and existing hosts will remain in the inventory However there will be downtime for
virtual center Remember to backup the databases as during the upgrade process the database schemas are changed
and in the event of a upgrade failure you will not be able to roll back and you will have to do a restore Refer to
Upgrade Guide for more details
Q30) When we hot add memory to a powered on VM will the swap file get dynamically increased
When we hot add memory to a powered on VM the swap file size will get dynamically increase
Q31) When we hot add memory to a powered on VM and the swap file get dynamically increased what
happens if there is not enough disk space to meet the growing vswap file size
7
You will not be able to add memory to that VM that has not enough memory for the swap file to grow and you will
receive an error
Q32) Can we add USB controllers to our VM in ESXESXi 4
Yes we now have the ability to hot plug USB controller into our VMs while they are running However the usb device
has to be connected to the ESX Server and not the client local machine
Q33) When installing convertor plug-in I get a 404 error and the installation halts
During installation of vCenter Convertor you will have to enter the FQDN instead of the IP address or netbios name as
this may cause you to receive the 404 error when installing the vCenter convertor plug-in later
Q34) Where is Distributed Power Management configured and what are the protocols it uses
DPM is configured and managed at the DRS cluster level It uses IPMI ILO and Wake On LAN protocols DRS can
use DPM to put under utilized hosts into standby modes to save power consumption
Q35) What is new with vCenter 4 user access and role management as compared to the virtual center
25
vCenter 4 allows us the ability to assign administrators to inventory objects such as networks and datastores which
were not available with the previous virtual center version
Q36) What are the new tasks we can schedule in vCenter 4 task scheduler
vCenter 4 task scheduler allows us the ability to schedule a task to increase the resources in a resource pool or
virtual machine This would be good to cater to the needs of virtual machines that will require additional ad-hoc
resources such as finance department doing month end closing which may result in resources surge on their
machines
Q37) How does VMware HA on an ESXi Server sends out heart beat if ESXi does not have a service
console
VMware HA clusters configured for ESXi Servers uses the vmkernel present on all ESXi Servers to send and receive
heart beats Whereas on ESX Servers the heartbeat is send and receive through the service console Therefore we
may not want to cluster ESX and ESXi Servers together in the same cluster
Q38) Can we create a cluster with ESX and ESXi Servers
Yes However VMware HA may not work as both servers uses different port groups to send out heart beats Vmotion
and DRS may still work This is not a supported practise
Q39) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q40) How can I grow an existing VMFS LUN without creating an extent or physical partition
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
2 of 10 232012 713 AM
Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
3 of 10 232012 713 AM
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
4 of 10 232012 713 AM
9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Q7) What is the different between VMware Data Protection as compared to the traditional VMware
Consolidated Backup
VMware Data Protection supports all storage architecture for backup and restore via LAN and SAN It also supports
full incremental and differential file level backup options
Q8) What is the key driving factor for users adopting VMware vCenter Data Recovery
Its an API that runs in a virtual machine within your vCenter it provides agentless backup and can backup virtual
machines even when they are being vmotion to a different host
Q9) Can we perform Storage Vmotion now via the GUI inside vCenter
Yes Storage Vmotion feature is now avaliable in the vSphere Client connected to vCenter Server It provides full
support for FC SAN and NFS
Q10) When using vCenter Linked Mode feature what are the functions that could be shared among the
vCenters in this link
vCenter Linked Mode allows administrator to centrally manage all the vCenter within a single view roles and licenses
can be shared across the vCenters configured in a link
Q11) Do I still require a Flexnet License Server if all my ESX Servers are ESX 4 and ESXi 4
No you no longer require a license server for the to manage the new ESX Servers All licenses are managed within the
vCenter Server
5
Q12) If my customer has a hybrid environment where they still have ESX 3 and ESX 35 can vCenter
communicate with the existing Flexnet License Server
Yes vCenter can communicate with existing license servers so as to allow it to manage legacy ESX Servers vCenter
will pull the licenses for legacy hosts from the flexnet license server
Q13) Why am I unable to hot add CPU and memory to virtual machine
You are required to enable this function under the virtual machine settings in order to use it Therefore it is advisable
to enable it before you start your virtual machine for the very first time
Q14) Is it true we can now use the new VMware Update Manager to upgrade our legacy ESX Servers
(For example ESX 35) to ESX 40 version
Yes the new VUM has the ability to upgrade your legacy ESX Server hosts for you However if you are upgrading a
standalone host you will be required to power off all virtual machines running on that host
Q15) How come we are unable to use our existing VI Client to manage our ESX 4 and vCenter 4
No the legacy VI Client is unable to manage newer ESX Server Hosts and vCenter You will need to install vSphere
Client to manage newer ESX Server Hosts and vCenter as well as legacy ESX Hosts
Q16) In vSphere can we configure bidirectional CHAP authentication for iSCSI
Yes we can now configure bidirectional CHAP authenticaton for iSCSI software It is fully supported Previously we
could only configure unidirectional CHAP authentication
Q17) Do we still need to configure a Service Console port for iSCSI initiator
No we no longer need a Service Console for software iSCSI initator The vmkiscsid no longer runs in the Service
Console There have been improvements made to the new iSCSI stack in the kernel and also with the use of TCPIP2
which has multi threading capabilities
Q18) What is the maximum number of CPU and maximum amount of memory a virtual machine can
scale
In vSphere a virtual machine can now be configure with a maximum of 8 virtual CPUs and 255 GB of memory
Q19) What is the maximum amount of logical CPUs and memory per ESX Server 4 host can scale
ESX Server 4 now supports a maximum of 64 logical CPUs and 1 TB of memory
Q20) What actions allow us to configure thin disk provisioning for a virtual machine
When we create a new virtual machine clone an existing virtual machine clone a template or perform Storage
Vmotion on an existing virtual machine
Q21) What is the benefit of configuring thin disk provisioning as compared to thick disk provisioning
for a virtual machine
When we configure thin disk provisioning the virtual machine only uses the space that it requires and not the entire
disk size this allows the remaining unused space for other virtual machines This enables us to do Storage Overcommitment
and use the storage more efficiently
6
Q22) Will my virtual machines still have connection if the virtual center that stores my Distributed
vSwitch configuration goes down
Yes this is because the Distributed vSwitch has an control plane which sits at the vCenter Server level and an IO
plane which are the form of hidden vSwitches sitting at the ESX level Therefore even if the vCenter goes down
virtual machines continue to have connectivity through the IO plane at the ESX level
Q23) What is the maximum number of ESX Hosts we can connect to a single distributed switch
We can connect up to 64 ESX hosts per distributed switch and vCenter 4 can support up a maximum of 16 distributed
switches Which means we can have up to 1024 hosts on these 16 distributed switches Refer to Configure
Maximums for more details
Q24) What is the version of the 64 bit Service Console running in ESX 4
The Service Console is a 26 linux kernel compatible with Red Hat Enterprise Linux 52 or CentOS 52 version
Q25) What is the maximum number of uplinks or ports per ESX 4 or ESXi 4 Host
The maximum number of uplinks per ESX 4 or ESXi 4 Host is 32 uplinks Refer to Configure Maximums for more
details
Q26) Can we install vCenter Server on a 64 bit Windows OS
Yes vCenter Server can be installed on both 32-bit and 64-bit Windows OS Refer to Compatibility matrix for more
details
Q27) Does ESXESXi 4 supports round robin multipathing policy
Yes besides fixed (preferred) and most recently used (MRU) ESXESXi 4 now supports round robin multipathing
policy and it has to be configured on the storage level
Q28) Can vCenter 4 support a cluster which includes ESX 3x and ESX 4 hosts
Yes we can cluster legacy ESX 3x hosts and ESX 4 hosts together in the same cluster vCenter will have to connect to
the flexnet license server to manage the licenses for the legacy hosts However new features such as hot add and PCI
pass through may not be avaliable to the VMs on legacy hosts Refer to Upgrade Guide for more details
Q29) When upgrading from virtual center 2x to vCenter 4 is there downtime for the host and do we
need to re add the ESX hosts back into the inventory
No theres no time for the hosts and existing hosts will remain in the inventory However there will be downtime for
virtual center Remember to backup the databases as during the upgrade process the database schemas are changed
and in the event of a upgrade failure you will not be able to roll back and you will have to do a restore Refer to
Upgrade Guide for more details
Q30) When we hot add memory to a powered on VM will the swap file get dynamically increased
When we hot add memory to a powered on VM the swap file size will get dynamically increase
Q31) When we hot add memory to a powered on VM and the swap file get dynamically increased what
happens if there is not enough disk space to meet the growing vswap file size
7
You will not be able to add memory to that VM that has not enough memory for the swap file to grow and you will
receive an error
Q32) Can we add USB controllers to our VM in ESXESXi 4
Yes we now have the ability to hot plug USB controller into our VMs while they are running However the usb device
has to be connected to the ESX Server and not the client local machine
Q33) When installing convertor plug-in I get a 404 error and the installation halts
During installation of vCenter Convertor you will have to enter the FQDN instead of the IP address or netbios name as
this may cause you to receive the 404 error when installing the vCenter convertor plug-in later
Q34) Where is Distributed Power Management configured and what are the protocols it uses
DPM is configured and managed at the DRS cluster level It uses IPMI ILO and Wake On LAN protocols DRS can
use DPM to put under utilized hosts into standby modes to save power consumption
Q35) What is new with vCenter 4 user access and role management as compared to the virtual center
25
vCenter 4 allows us the ability to assign administrators to inventory objects such as networks and datastores which
were not available with the previous virtual center version
Q36) What are the new tasks we can schedule in vCenter 4 task scheduler
vCenter 4 task scheduler allows us the ability to schedule a task to increase the resources in a resource pool or
virtual machine This would be good to cater to the needs of virtual machines that will require additional ad-hoc
resources such as finance department doing month end closing which may result in resources surge on their
machines
Q37) How does VMware HA on an ESXi Server sends out heart beat if ESXi does not have a service
console
VMware HA clusters configured for ESXi Servers uses the vmkernel present on all ESXi Servers to send and receive
heart beats Whereas on ESX Servers the heartbeat is send and receive through the service console Therefore we
may not want to cluster ESX and ESXi Servers together in the same cluster
Q38) Can we create a cluster with ESX and ESXi Servers
Yes However VMware HA may not work as both servers uses different port groups to send out heart beats Vmotion
and DRS may still work This is not a supported practise
Q39) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q40) How can I grow an existing VMFS LUN without creating an extent or physical partition
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
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Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
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no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
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VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
No the legacy VI Client is unable to manage newer ESX Server Hosts and vCenter You will need to install vSphere
Client to manage newer ESX Server Hosts and vCenter as well as legacy ESX Hosts
Q16) In vSphere can we configure bidirectional CHAP authentication for iSCSI
Yes we can now configure bidirectional CHAP authenticaton for iSCSI software It is fully supported Previously we
could only configure unidirectional CHAP authentication
Q17) Do we still need to configure a Service Console port for iSCSI initiator
No we no longer need a Service Console for software iSCSI initator The vmkiscsid no longer runs in the Service
Console There have been improvements made to the new iSCSI stack in the kernel and also with the use of TCPIP2
which has multi threading capabilities
Q18) What is the maximum number of CPU and maximum amount of memory a virtual machine can
scale
In vSphere a virtual machine can now be configure with a maximum of 8 virtual CPUs and 255 GB of memory
Q19) What is the maximum amount of logical CPUs and memory per ESX Server 4 host can scale
ESX Server 4 now supports a maximum of 64 logical CPUs and 1 TB of memory
Q20) What actions allow us to configure thin disk provisioning for a virtual machine
When we create a new virtual machine clone an existing virtual machine clone a template or perform Storage
Vmotion on an existing virtual machine
Q21) What is the benefit of configuring thin disk provisioning as compared to thick disk provisioning
for a virtual machine
When we configure thin disk provisioning the virtual machine only uses the space that it requires and not the entire
disk size this allows the remaining unused space for other virtual machines This enables us to do Storage Overcommitment
and use the storage more efficiently
6
Q22) Will my virtual machines still have connection if the virtual center that stores my Distributed
vSwitch configuration goes down
Yes this is because the Distributed vSwitch has an control plane which sits at the vCenter Server level and an IO
plane which are the form of hidden vSwitches sitting at the ESX level Therefore even if the vCenter goes down
virtual machines continue to have connectivity through the IO plane at the ESX level
Q23) What is the maximum number of ESX Hosts we can connect to a single distributed switch
We can connect up to 64 ESX hosts per distributed switch and vCenter 4 can support up a maximum of 16 distributed
switches Which means we can have up to 1024 hosts on these 16 distributed switches Refer to Configure
Maximums for more details
Q24) What is the version of the 64 bit Service Console running in ESX 4
The Service Console is a 26 linux kernel compatible with Red Hat Enterprise Linux 52 or CentOS 52 version
Q25) What is the maximum number of uplinks or ports per ESX 4 or ESXi 4 Host
The maximum number of uplinks per ESX 4 or ESXi 4 Host is 32 uplinks Refer to Configure Maximums for more
details
Q26) Can we install vCenter Server on a 64 bit Windows OS
Yes vCenter Server can be installed on both 32-bit and 64-bit Windows OS Refer to Compatibility matrix for more
details
Q27) Does ESXESXi 4 supports round robin multipathing policy
Yes besides fixed (preferred) and most recently used (MRU) ESXESXi 4 now supports round robin multipathing
policy and it has to be configured on the storage level
Q28) Can vCenter 4 support a cluster which includes ESX 3x and ESX 4 hosts
Yes we can cluster legacy ESX 3x hosts and ESX 4 hosts together in the same cluster vCenter will have to connect to
the flexnet license server to manage the licenses for the legacy hosts However new features such as hot add and PCI
pass through may not be avaliable to the VMs on legacy hosts Refer to Upgrade Guide for more details
Q29) When upgrading from virtual center 2x to vCenter 4 is there downtime for the host and do we
need to re add the ESX hosts back into the inventory
No theres no time for the hosts and existing hosts will remain in the inventory However there will be downtime for
virtual center Remember to backup the databases as during the upgrade process the database schemas are changed
and in the event of a upgrade failure you will not be able to roll back and you will have to do a restore Refer to
Upgrade Guide for more details
Q30) When we hot add memory to a powered on VM will the swap file get dynamically increased
When we hot add memory to a powered on VM the swap file size will get dynamically increase
Q31) When we hot add memory to a powered on VM and the swap file get dynamically increased what
happens if there is not enough disk space to meet the growing vswap file size
7
You will not be able to add memory to that VM that has not enough memory for the swap file to grow and you will
receive an error
Q32) Can we add USB controllers to our VM in ESXESXi 4
Yes we now have the ability to hot plug USB controller into our VMs while they are running However the usb device
has to be connected to the ESX Server and not the client local machine
Q33) When installing convertor plug-in I get a 404 error and the installation halts
During installation of vCenter Convertor you will have to enter the FQDN instead of the IP address or netbios name as
this may cause you to receive the 404 error when installing the vCenter convertor plug-in later
Q34) Where is Distributed Power Management configured and what are the protocols it uses
DPM is configured and managed at the DRS cluster level It uses IPMI ILO and Wake On LAN protocols DRS can
use DPM to put under utilized hosts into standby modes to save power consumption
Q35) What is new with vCenter 4 user access and role management as compared to the virtual center
25
vCenter 4 allows us the ability to assign administrators to inventory objects such as networks and datastores which
were not available with the previous virtual center version
Q36) What are the new tasks we can schedule in vCenter 4 task scheduler
vCenter 4 task scheduler allows us the ability to schedule a task to increase the resources in a resource pool or
virtual machine This would be good to cater to the needs of virtual machines that will require additional ad-hoc
resources such as finance department doing month end closing which may result in resources surge on their
machines
Q37) How does VMware HA on an ESXi Server sends out heart beat if ESXi does not have a service
console
VMware HA clusters configured for ESXi Servers uses the vmkernel present on all ESXi Servers to send and receive
heart beats Whereas on ESX Servers the heartbeat is send and receive through the service console Therefore we
may not want to cluster ESX and ESXi Servers together in the same cluster
Q38) Can we create a cluster with ESX and ESXi Servers
Yes However VMware HA may not work as both servers uses different port groups to send out heart beats Vmotion
and DRS may still work This is not a supported practise
Q39) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q40) How can I grow an existing VMFS LUN without creating an extent or physical partition
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
3 of 10 232012 713 AM
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
switches Which means we can have up to 1024 hosts on these 16 distributed switches Refer to Configure
Maximums for more details
Q24) What is the version of the 64 bit Service Console running in ESX 4
The Service Console is a 26 linux kernel compatible with Red Hat Enterprise Linux 52 or CentOS 52 version
Q25) What is the maximum number of uplinks or ports per ESX 4 or ESXi 4 Host
The maximum number of uplinks per ESX 4 or ESXi 4 Host is 32 uplinks Refer to Configure Maximums for more
details
Q26) Can we install vCenter Server on a 64 bit Windows OS
Yes vCenter Server can be installed on both 32-bit and 64-bit Windows OS Refer to Compatibility matrix for more
details
Q27) Does ESXESXi 4 supports round robin multipathing policy
Yes besides fixed (preferred) and most recently used (MRU) ESXESXi 4 now supports round robin multipathing
policy and it has to be configured on the storage level
Q28) Can vCenter 4 support a cluster which includes ESX 3x and ESX 4 hosts
Yes we can cluster legacy ESX 3x hosts and ESX 4 hosts together in the same cluster vCenter will have to connect to
the flexnet license server to manage the licenses for the legacy hosts However new features such as hot add and PCI
pass through may not be avaliable to the VMs on legacy hosts Refer to Upgrade Guide for more details
Q29) When upgrading from virtual center 2x to vCenter 4 is there downtime for the host and do we
need to re add the ESX hosts back into the inventory
No theres no time for the hosts and existing hosts will remain in the inventory However there will be downtime for
virtual center Remember to backup the databases as during the upgrade process the database schemas are changed
and in the event of a upgrade failure you will not be able to roll back and you will have to do a restore Refer to
Upgrade Guide for more details
Q30) When we hot add memory to a powered on VM will the swap file get dynamically increased
When we hot add memory to a powered on VM the swap file size will get dynamically increase
Q31) When we hot add memory to a powered on VM and the swap file get dynamically increased what
happens if there is not enough disk space to meet the growing vswap file size
7
You will not be able to add memory to that VM that has not enough memory for the swap file to grow and you will
receive an error
Q32) Can we add USB controllers to our VM in ESXESXi 4
Yes we now have the ability to hot plug USB controller into our VMs while they are running However the usb device
has to be connected to the ESX Server and not the client local machine
Q33) When installing convertor plug-in I get a 404 error and the installation halts
During installation of vCenter Convertor you will have to enter the FQDN instead of the IP address or netbios name as
this may cause you to receive the 404 error when installing the vCenter convertor plug-in later
Q34) Where is Distributed Power Management configured and what are the protocols it uses
DPM is configured and managed at the DRS cluster level It uses IPMI ILO and Wake On LAN protocols DRS can
use DPM to put under utilized hosts into standby modes to save power consumption
Q35) What is new with vCenter 4 user access and role management as compared to the virtual center
25
vCenter 4 allows us the ability to assign administrators to inventory objects such as networks and datastores which
were not available with the previous virtual center version
Q36) What are the new tasks we can schedule in vCenter 4 task scheduler
vCenter 4 task scheduler allows us the ability to schedule a task to increase the resources in a resource pool or
virtual machine This would be good to cater to the needs of virtual machines that will require additional ad-hoc
resources such as finance department doing month end closing which may result in resources surge on their
machines
Q37) How does VMware HA on an ESXi Server sends out heart beat if ESXi does not have a service
console
VMware HA clusters configured for ESXi Servers uses the vmkernel present on all ESXi Servers to send and receive
heart beats Whereas on ESX Servers the heartbeat is send and receive through the service console Therefore we
may not want to cluster ESX and ESXi Servers together in the same cluster
Q38) Can we create a cluster with ESX and ESXi Servers
Yes However VMware HA may not work as both servers uses different port groups to send out heart beats Vmotion
and DRS may still work This is not a supported practise
Q39) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q40) How can I grow an existing VMFS LUN without creating an extent or physical partition
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
2 of 10 232012 713 AM
Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
3 of 10 232012 713 AM
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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4 of 10 232012 713 AM
9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Q32) Can we add USB controllers to our VM in ESXESXi 4
Yes we now have the ability to hot plug USB controller into our VMs while they are running However the usb device
has to be connected to the ESX Server and not the client local machine
Q33) When installing convertor plug-in I get a 404 error and the installation halts
During installation of vCenter Convertor you will have to enter the FQDN instead of the IP address or netbios name as
this may cause you to receive the 404 error when installing the vCenter convertor plug-in later
Q34) Where is Distributed Power Management configured and what are the protocols it uses
DPM is configured and managed at the DRS cluster level It uses IPMI ILO and Wake On LAN protocols DRS can
use DPM to put under utilized hosts into standby modes to save power consumption
Q35) What is new with vCenter 4 user access and role management as compared to the virtual center
25
vCenter 4 allows us the ability to assign administrators to inventory objects such as networks and datastores which
were not available with the previous virtual center version
Q36) What are the new tasks we can schedule in vCenter 4 task scheduler
vCenter 4 task scheduler allows us the ability to schedule a task to increase the resources in a resource pool or
virtual machine This would be good to cater to the needs of virtual machines that will require additional ad-hoc
resources such as finance department doing month end closing which may result in resources surge on their
machines
Q37) How does VMware HA on an ESXi Server sends out heart beat if ESXi does not have a service
console
VMware HA clusters configured for ESXi Servers uses the vmkernel present on all ESXi Servers to send and receive
heart beats Whereas on ESX Servers the heartbeat is send and receive through the service console Therefore we
may not want to cluster ESX and ESXi Servers together in the same cluster
Q38) Can we create a cluster with ESX and ESXi Servers
Yes However VMware HA may not work as both servers uses different port groups to send out heart beats Vmotion
and DRS may still work This is not a supported practise
Q39) What is the limitation for configuring VMware Fault Tolerance for a virtual machine
Virtual machine selected for VMware FT must be provisioned with thick disk and not thin disk if it was provisioned
with thin disk there will be a prompt to inflate the existing disk size
Q40) How can I grow an existing VMFS LUN without creating an extent or physical partition
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
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no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
We can use the grow function to grow an existing VMFS LUN If the LUN is out of space first we must get the storage
administrator to grow the same LUN on the storage level with storage array management utilities then within the
8
vCenter Server we can then select the LUN and grow it
Q41) How come the hot add CPU and hot add memory option is greyed out for my VM
This feature is currently available only on supported guest OS such as Windows Server 2003 enterprise and Windows
2008 datacenter edition The type of license also plays a part on the availability of this feature to the VM
Q42) What does the channel number stands for in vmhbaTCL
The only real example that Ive seen in vSphere so far is the software iSCSI initiator If you give the VMkernel
multiple VMkernel ports and each port can reach (over its own subnet) different targets they are listed with different
channel numbers to indicate whether they use the first VMkernel port the second or the third
Q43) Can we install VMware Consolidated Backup VCB in a virtual machine
Yes VCB can now be installed in a VM and it can be use to backup VMs running on iSCSI and NFS However if you
wish to backup VMs whose files reside on an FC San LUN VCB must be installed on a physical machine
Q44) Does VMware View 3 work with VMware vSphere 4
No currently VMware View 3 is only supported on VI 35 infrastructure and it is not supported to work with vSphere
4 environment
Q45) Is the Service Console root file system still running on ext3 file system
No the SC root file system is now running on VMDK and this is automatically created during initial installation of
ESX Servers
Q46) Is it possible to configure VMware Update Manager 4 to point to WSUS to grab windows updates
No this is not possible as the VUM Server is unable to communicate with the WSUS Server
Q47) Can vCenter 4 perform Storage Vmotion on a legacy ESX 3x Host and convert the VM virtual disk
from thick to thin disk
Yes vCenter 4 is able to convert a VMs virtual disk from thick to thin using storage vmotion Refer to this ESX 3x
and vCenter 4 SVmotion for more detail discussion
Q48) I understand that Oracle databases licensed by per CPU how does that translate to the number of
license I have to purchase if I port it over to VM
In order for you to run your Oracle DB within a VM on that ESX Server you have to purchase license for each physical
CPU on that ESX Server box Refer to this Oracle Licensing Per Processor for more detail discussion
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
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Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
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no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Q49) How come there is no standalone boot CD for VMware Convertor 40 for me to download for use
for cold cloning
VMware vCenter Converter Standalone 401 does not support cold cloning you must use an earlier Converter edition
boot CD 30x Enterprise Edition Refer to this VMware Convertor User Guide for more information
Q50) When we convert a VM from thin disk to thick disk which state must the VM be in to perform the
request
9
The VM must be in the powered off state in order to be converted from thin to thick disk
Q51) What is the default multipathing policy for ESX 4
The hypervisor determines whether to use MRU or Fixed based on the type of arrays it detects If array is
activepassive it would be treated as MRU If array is activeactive it would be treated as fixed Refer to Multipathing
Policies in ESX 4 for more details
Q52) What is the difference between Enhanced vmxnet and vmxnet3
Vmxnet3 is an improved version of enhanced vmxnet some benefits and improvements are MSIMSI-X support Side
Scaling checksum and TCP Segmentation Offloading (TSO) over IPv6 off-loading and Large TXRX ring sizes
Refer to Vmxnet3 tips and tricks for more details
Q53) When we replicate the LUNs over resignaturing only occurs for VMFS LUNs and not RDM how do
we get the replicated RDM to work
You can replicate the RDM to a new array but the mapping file that is configured on the vm itself will no longer be
pointing to the same location it was previously so the RDM has to be re-mapped to the VM in a DR scenario
Q54) After installing plug-in inside the VC I am unable to enable the plug-in and it always shows as
disabled
Go to servicesmsc ensure that the Virtual Center Management Webservices is running and then relogin the vSphere
Client and enable the plug-in
Q55) What is the difference between ephemeral and dynamic binding on a distributed virtual switch
Ephemeral a new port on every power-on The port is destroyed when the VM disconnects from the port Dynamic
assign a port when the VM is powered on it uses a concept similar to DHCP in that if the same port is available then
it will renew that one Refer to Networking Deep Dive for more details
Q56) What is the difference between a thick virtual disk and eager zeroed thick virtual disk
Thick virtual disk does not format the VMDK at the time of deployment This means that data which needs to be
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
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Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
written must pause while the blocks required to store the data are zeroed out An eager zeroed thick virtual disk
actually formats all of its data blocks at the time of deployment
Q57) What kind of permissions do we need to provide when configuring a NAS Server
We need to configure permission for the administrator group account rights on the NAS Server so that the ESX Server
can access the NAS Server
Q58) Storage View tabs in the SAN storage datastore is blank and does not show anything
Start the vCenter Mount Service and virtual disk service then restart the vCenter Server service on the Windows OS
Then click on refresh for the storage view tabs
Q59) Can we migrate VMs running on ESX host with VMware Hardware Version 7 to ESX host with VMware Hardware Version 4
No we cannot migrate VMs running on hardware version 7 back to hardware version 4 VMware hardware version 7
10)only exists on ESX4 and greater However it is possible to migrate VMs running on ESX host with hardware version 4
to ESX host running on hardware version 7
Q60) Does VMware have an online page where we can search for all the technical white papers
Yes Please kindly refer to Technical Resource Center for more information
Q61) Does VCB supports Windows Server 2008
VCB version 15 supports Windows Server 2008 Refer to VCB 15 Update 1 release notes for more information
11VMware_Interview_Questionsdoc
NOTE I dont know answers to some of the questions in the doc so if anyone of you aware of the
answer for any particular question please send me an email with the question and answer I will
update it in the doc Email charanisupportyounet
1 Explain the physical topology of Virtual Infrastructure 3 Data Centre
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86
computing servers storage networks and arrays IP networks a management server and desktop
clients
2 How do you configure Clusters Hosts and Resource Pools in VI3
A cluster is a group of servers working together closely as a single server to provide high availability
load balancing and high performance A host is a single x86 computing server with individual computing
and memory resources Resource pools are allocation of the available resources in to pieces for the
proper distribution
3 What are resource pools amp whatrsquos the advantage of implementing them
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
3 of 10 232012 713 AM
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
A VMware ESX Resource pool is a pool of CPU and memory resources Inside the pool resources are
allocated based on the CPU and memory shares that are defined This pool can have associated access
control and permissions Clear management of resources to the virtual machines
4 Explain why VMware ESX Server is preferred over Virtual Server or Workstation for
enterprise implementation
For better resource management as it has a virtualization layer involved in its kernel which
communicates with the hardware directly
5 In what different scenarios or methods can you manage a VI3
Using the Virtual Infrastructure Client we can manage one esx server using virtual center we can
manage more than 1 esx server and also we can use service console to manage it
httpsearchvmwaretechtargetcomtip0289483sid179_gci1280576_mem100html
6 Explain the difference between access through Virtual Infrastructure Client (vi client) Web
access Service Console access(ssh)
Using VI Client we can access the ESX server as well as Virtual Center Server also here we can use
unix type of authentication or windows type authentication But to access the service console we should
use unix type of authentication preferably even though we can access the service console through ad
authentication using esxcfg-auth but it does not support all functions to work on all the functions are
available only with root account which is based on red hat Linux kernel Using the web access also we
can manage virtual center as well as a single host But all the enterprise features are not supported
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and
you must know Linux to accomplish your task (no GUI)
SSH to the Service Console
You can SSH to the console prompt of an ESX server and receive the same Linux text
console access as I showed above Telnet is not allowed To use this method the ESX
server must be working on the network and you must have an SSH client on your PC to
connect Again in this mode you dont get a GUI interface
VMware Virtual Infrastructure (VI) Web Access to the ESX Server
This is the VMware VI Web Access interface The benefit to using this is that you get a GUI
client for your ESX server without having to install a client on your local machine The
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1 of 10 232012 713 AM
downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
2 of 10 232012 713 AM
Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
3 of 10 232012 713 AM
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
client for your ESX server without having to install a client on your local machine The
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1 of 10 232012 713 AM
downside to the web interface is that you can only perform basic ESX functions like
controlling existing machines (startstoppause) and console remote access You cannot
add new VMs work with VM storage or VM networks Still this is a great interface if you
just need to check the status of your ESX VMs restart a VM or use console remote control
VMware Virtual Infrastructure Client (VI Client) to the Server
The benefits to the VI client are that you have full access to do whatever is needed on the
ESX Server and you get a GUI client to do it in The only downside is that you must install
the VI client application to do this However the installation is negligible and the VI client
is the absolute best way to administer your ESX Server
VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)
From this VI VC interface you can manage all ESX servers VM storage VM networks and more
Virtual Center of course is an optional product that requires additional licenses and hardware
7 Explain advantages or features of VMware Virtual Machine File System (VMFS)
Itrsquos a clustered file system excellent support for sharing between ESX servers in a cluster
Features
Allows access by multiple ESX Servers at the same time by implementing per-file locking SCSI
Reservations are only implemented when LUN meta data is updated (eg file name change file size
change etc)
Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts
LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS
volume on the fly (by spanning multiple VMFS volumes)
With ESXESXi4 VMFS volumes also can be expanded using LUN expansion
Optimize your virtual machine IO with adjustable volume disk file and block sizes
Recover virtual machines faster and more reliably in the event of server failure with Distributed
journaling
Limitations
Can be shared with up to 32 ESX Servers
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
2 of 10 232012 713 AM
Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
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3 of 10 232012 713 AM
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere)
There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers For
instance if there is a tree of disks off the same base disk with 40 leaf nodes in the tree all 40 leaf
nodes can be simultaneously run but they can only run on up to 8 ESX hosts
VMFS-3 limits files to 262144 (2
18
) blocks which translates to 256 GB for 1 MB block sizes (the
default) up to 2 TB for 8 MB block sizes
8 What are the types of data stores supported in ESX35
iSCSI datastores FC SAN datastores Local VMFS NAS and NFS
9 How can you configure these different types of datastores on ESX35
If we have FC cards installed on the esx servers by going to the storage option we can scan for the
luns
10What is Vmware Consolidate Backup (VCB) Explain your work exposure in this area
VMware Consolidated Backup is a backup framework which enables 3
rd
party tools to take backups
VCB is used to help you backup your VMware ESX virtual servers Essentially VCB is a backup proxy
server It is not backup software If you use VCB you still need backup software It is commonly
installed on its own dedicated Windows physical server
Here are the benefits of VMwares VCB
Centralize backups of VMware ESX Virtual Servers
Provide file-level backups of VMware ESX Virtual Servers - both full and incremental (file level
backup available to only Windows guests)
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Provide image-level backups
Prevent you from having to load a backup agent on every Virtual Machine
Prevent you from having to shutdown Virtual Machines to get a backup
Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
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Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
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no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
channel adaptor
Provides centralized storage of Virtual Server backups on the VCB server that is then moved to
your backup tapes through the 3rd party backup agent you install
Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on
either the VMware ESX service console or on each virtual machine
Utilizes VMware Snapshots
Basically here is how VCB works
If you are doing a file level backup VCB does a snapshot of the VM mounts the snapshot and
allows you to backup that mounted drive through VCB to your 3rd party backup software
If you are doing an image level backup of the VM VCB does a snapshot of the VM copies the
snapshot to the VCB server unsnaps the VM and allows you to backup the copied snapshot
image with your 3rd party backup software
11 How do you configure VMware Virtual Centre Management Server for HA amp DRS What
are the conditions to be satisfied for this setup
HA amp DRS are the properties of a Cluster A Cluster can be created only when more than one host
added in that case we need to configure HA amp DRS as well to provide High Availability and Load
balancing between hosts and for the virtual machines
12Explain your work related to below terms
VM Provisioning Virtual Machine Creation
Alarms amp Event Management Alarms are used to know the status of the resource usage for a VM
Events are used monitor the tasks that are taken place on the esx servers or in the virtual center
Task Scheduler Task scheduler if you want to schedule a task it will be used for example if you want
move one vm from one host to another host or if you want shutdownreboot a vm etc
Hardware Compatibility List what are the hardware that compatible with ESX OS
13What SAN or NAS boxes have you configured VMware with How did you do that
Storage team will provide the LUN information with that we will add those LUNs to ESX hosts from VM
storage
14What kind of applications or setups you have on you Virtual Machines
Exchange server and Share Point but these are for DEMO purposes Cirtrix presentation servers etc
15 Have you ever faced ESX server crashing and Virtual Centre Server crash How do you
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
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Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
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no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
know the cause of these crashes in these cases
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
16 Will HA work if Virtual Center Server is down
A1) HA continues to work if VC is down - the agents are initially configured by virtual center but HA
operations are controlled by local agents on ESX VC does NOT monitor the ESX servers for HA ESX
servers monitor each other
DRS do not work while VC is down
A2) For DRS the config and logic is completely in VC
For HA only the config is in VC The logic is in the service consoles and thats where the reaction is
coming from VC will notice the HA reaction afterwards when it connects to the service consoles the next
time
No Why because all these futures are comes with Virtual Center only
17 What are the situations which triggers vMotion automatically
Resource Contention between virtual machines (DRS)
Distributed power management
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
3 of 10 232012 713 AM
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
18 What is DRSHADPMdvSwitchFTvAppsvSafevShields -)
DRS Distributed Resource Scheduling
HA High Availability
DPM Distributed Power Management
dvSwitch Distribute vSwitch ndash Itrsquos a new feature introduced in vSphere40
FT Fault Tolerance for Virtual Machines ndash itrsquos a new feature introduced in vSphere40
vApps vApp is a container same as resource pool but it is having some features of virtual machines a
vApp can be powered on or powered off and it can be cloned too
httpcommunitiesvmwarecommessage13084571308457
vmSafe VMsafes application programming interfaces are designed to help third-party vendors create
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
4 of 10 232012 713 AM
9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
virtualization security products that better secure VMware ESX vShield Zones is a security tool targets
the VMware administrator
vShield VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual
network traffic This three-part series describes vShield Zones explains how to install it and provides
useful management tips To begin lets get started with the basics what vShield Zones is and how it
works
httpsearchvmwaretechtargetcomtip0289483sid179_gci1363051_mem100html
19 What are the requirement for FT
httpcommunitiesvmwarecomthread209955
20 What are the differences between ESX and ESXi
ESX is an OS with full features of virtualization ESXi is a limited features OS with 32MB image
21 Which are the new features introduced in vSphere 4
1 64-bit hypervisor - Although not everyone realized it the hypervisor in ESX Server 35 was 32-bit
As a result ESX Server 35 couldnt take full advantage of todays more powerful 64-bit hardware
platforms ESX Server 40 uses a native 64-bit hypervisor that provides significant performance and
scalability enhancements over the previous versions However the new hypervisor does require a 64-bit
hardware platform
2 Increased VM scalability - ESX Server 40s new 64-bit architecture provides significant increases
in scalability ESX Server 40 supports virtual machines (VMs) with up to 255GB of RAM per VM In
addition the vSphere 40 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM
The other editions support up to 4-way virtual SMP These gains are available on both Windows and
Linux guests
3 Hot add CPU RAM and virtual disks - This important enhancement in vSphere 40 is designed to
create a dynamic IT infrastructure through the ability to add CPU RAM and virtual disks to a running
VM The hot add capability lets you dynamically increase your VMs performance during periods of high
resource demands
4 Thin provisioning - This feature is nothing new to Microsoft virtualization users vSphere now
offers a thin-provisioning feature thats essentially the equivalent of Hyper-Vs dynamic disks Thin
provisioning lets you create and provision a Virtual Hard Disk (VHD) but the host uses only the amount
of storage thats actually required by the VM rather than using the VHDs allocated size
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
4 of 10 232012 713 AM
9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
5 VMware Fault Tolerance - Fault Tolerance is a new high-availability feature in vSphere 40 Fault
Tolerance works only between two systems It uses a technology called vLockstep to provide protection
from system failure with absolutely no downtime VMwares vLockstep technology keeps the RAM and
the virtual processors of two VMs in sync at the instruction level
6 vNetwork Distributed SwitchmdashvSphere 40s vNetwork Distributed Switch lets you create and
share network configurations between multiple servers The vNetwork Distributed Switch spans multiple
ESX Server hosts letting you configure and manage virtual networks at the cluster level It also lets
you move network configuration and state with a VM when the VM is live migrated between ESX Server
hosts
7 IPv6 support - Another enhancement in vSphere 40 is support for IPv6 Many organizations are
planning to move to IPv6 vSpheres IPv6 support lets customers manage vCenter Server and ESX
Server hosts in mixed IPv4IPv6 network environments
8 vAppsmdashvApps essentially lets you manage as a single entity multiple servers that comprise an
n-tiered application Using vApps you can combine multiple VMs their interdependencies and their
resource allocations together as a unit You can manage all the components of the vApps as a single
unit letting you power off clone and deploy all the vApps components in the same operations
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4 of 10 232012 713 AM
9 vSphere Host Update UtilitymdashThe new vSphere Host Update Utility lets you centrally update your
ESXi and ESX Server 30 and later hosts to ESX Server 40 The UI displays the status of the remote
updates in real time
10 VMware vShield ZonesmdashVMwares new vShield Zones let customers enforce network access
protection between VMs running in the virtual data center The vShield Zones feature lets you isolate
bridge and firewall traffic across vCenter deployments
22 Which are the traffic shaping options available to configure
23 What is promiscuous mode
If the promiscuous mode is enabled for a switch the traffic sent that switch will be visible to all vmrsquos
connected to that switch I mean the data will be broadcasted
24 What makes iSCSI and FC diffrent
Addressing Scheme iSCSI relies on IP and FC not and the type of transfer of data also In FC the data
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
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no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
transferred as blocks in iSCSI the data transferred as files The cabling also FC uses Fibre cable and
iSCSI uses RJ45
25 What is the format for iSCSI addressing
IP Address
26 VMs Task Manager shows performance normal But vCenter reports high resource
utilization what is the reason
Search KEY WORDS VMs performance normal vCenter reports high resource utilization
httpcommunitiesvmwarecommessage897975
27 What are the different types of memory management tricks available under ESX
httpenwordpresscomtagesx-memory-management
httpwwwcsnorthwesternedu~fabianbclassescs-443-s05ESXpps
28 What is vmmemctl
httppubsvmwarecomvi3resmgmtwwhelpwwhimplcommonhtmlwwhelphtmcontext=resmgmtamp
file=vc_advanced_mgmt1124html
29 How we can list pNICs amp status using command line
ifconfig ndasha
30 What is resource pool What are the use of it
A resource pool is a logical abstraction for flexible management of resources Resource pools can be
grouped into hierarchies and used to hierarchically partition available CPU and memory resources
31 Ask about how HA works
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on
into a cluster Hosts in the cluster are monitored and in the event of a failure the virtual machines on a
failed host are restarted on alternate hosts
32 Is HA dependent on virtual center
(Only for Install)
33 What is the Maximum Host Failure allowed in a cluster
(4)
34 How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)
35How many iSCSI targets will ESX support
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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5 of 10 232012 713 AM
(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
8 for 301 (64 for 35)
36 How Many Fiber Channel targets
(256) (128 on Install)
37 What is Vmotion
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(ability to move running vm from one host to another)
38 What is virtual SMP ndash
when and why should you give a vm multiple vCPUs - part of their answer whould be that best pracrtice
is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling
39 Ask what version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel - and
give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent
3 -
40 does HA use vmotion
the answer is no - vm stops and restarts on ESX other host
41 what is the different when you use viclient connect to VC and directly to ESX server itself
When you connect to VC you manage ESX server via vpxa (Agent on esx server) Vpxa then pass those
request to hostd (management service on esx server) When you connect to ESX server directly you
connect to hostd (bypass vpxa) You can extend this to a trobleshoot case where connect to esx see one
thing and connect to VC see another So the problem is most likely out of sync between hostd and vpxa
service vmware-vpxa restart should take care of it
42 What was the most difficult VMWare related problemissue you faced in a production
environment and what were the specific steps you took to resolve it
HA issues ndash because of dns problems the hosts are unable to communicate together Corrected by
adding all servers iprsquos in each serverrsquos etchosts file
VM was not powered up ndash because the swap file was locked by another host when I try to power on the
vm its not powering up After releasing the lock its powered on
43 When was the last time you called VM Support and what was the issue
Licensing related issues
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
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48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
44 What was the most performance intensive production app that you supported in VMware
and what were the some of the challenges that it posed
In exchange sharepoint demo project getting lot of VLAN issues (its my experience you can say yours)
45 How would you determine that a perf intensive app is a good candidate Spefically what
tools would you use to identify candidates Specifically inside those tools what metrics would
you use
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
46 What is yor philosophy on how much of the data center can be virtualized (If the
interviewer wants max virtualization but the interviewee is not convinced that this is a good
idea this could be a deal breaker)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
47 What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization
market)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
6 of 10 232012 713 AM
48 I beleive another good question would be to ask the candidate to briefly describe VST
VGT amp EST mode and 8021Q trunking I say this because networking is such an important
part of VMware implementations and on going support do you really want a VMware
engineer working in your environment if they lack the knowledge of these concepts (+unless
of course they are only delegated with low level permissions for generic VM operations+)
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
More information on these modes can be found here wwwvmwarecompdfesx3_vlan_wppdf
Also ask the candidate to explain why one mode would be used as opposed to another remember that
there can be numerous reasons for the use of different modes depending on your companyclients
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
network security policies etc
49 If you are interviewing for a consultant role it would also be a good scenario to provide a
brief overview of a fictional network and ask the candidate to do a whiteboard draft of how
the network would be layed out if say the ESX servers have 6 NICs or 8 NICs etc etc
Please send me the answer if anyone knows about this I will update the doc
charanisupportyounet
50 What are notable files that represent a VM
vmx ndash configuration settings for VM
vmxf ndash configuration settings used to support an XML-based VM configuration API
vmtx ndash configuration settings for a Template VM (replaces the vmx file)
vmdk ndash virtual disk file (Note if a thick disk is used a ndashflatvmdk file that represents the actual
monolithic disk file will exist but will be hidden from the vSphere Client)
nvram ndash non-volatile memory (BIOS)
vswp ndash swap file used by ESXESXi per VM to overcommit memory ie use more memory than
physically available This is created by the host automatically when powering on a VM and deleted
(default behavior) when powering off a VM Swap files can remain and take up space if a host failed
prior to shutting down a VM properly Normally the swap file is stored in the location where the VM
configuration files are kept however the location can be optionally located elsewheremdashfor example
locally for performance reasons and if using NASNFS local swap should be used
vmss ndash suspend file (if placed into vvmssdn ndashndash fsonra psnshaopts hfiolet management suspend power mode)
51 Host Profiles
What licensing is required for Host Profiles Available with vSphere Enterprise Plus edition
52 Can Host Profiles work with ESXESXi 3x hosts
No Only starting with ESXESXi 40
53 Can Host Profiles be used with a cluster running both ESX and ESXi hosts
Yes but remember to use an ESX host and not an ESXi host to create a profile for use
In theory Host Profiles should work with mixed host clusters as it translates ESX to ESXi but be
careful as there are enough differences between ESX and ESXi that can lead you to make
self-inflicted errors when applying Host Profiles The easiest method is to create clusters that are
homogeneous and maintain two different profiles for these two types of clusters
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
54 Can Host Profiles work when using the Cisco Nexus 1000v
No because Host Profiles was designed with the generic vNetwork Distributed Switch The Cisco
Nexus 1000v switch gives administrators finer-grained control of the networking beyond what
Host Profiles can apply
55 What are host profiles
A set of best practiced configuration rules which are can be applied to entire cluster or to an individual
host So that all the hosts in sync with each other this will avoid vmotion drs and ha problems
56 Could not power on VM no swap file
My ESXi 35 machine runs 8-10 VMs (Win2k3 and WinXP) normally At the moment 5 of them are
complaining that they cannot Power On They seem to start and then complain Could not power on VM
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
7 of 10 232012 713 AM
no swap file I had a look with the data browser Its a small installation so the vswp files ought to be in
the same directory as the vmx file (I did not inttionally put them anywhere else) Of course I dont see a
vswp file there because the machine is not running I dont know enough about the vmx file structure to
identify if anything is wrong in the specifications I have downloaded one of the vmx files and attached it
here Please either tell me what to change in that vmx file or suggest another approach to get the
machines to start
57 What are the available Storage options for virtual machines Raw device mappings
VMFS
httpsearchvmwaretechtargetcomtip0289483sid179_gci1318776_mem100html
58 What are the differences between Virtual and Physical compatibility modes when mapping
the Raw Devices to virtual machines
You can configure RDM in two ways
Virtual compatibility modemdashthis mode fully virtualizes the mapped device which appears to the
guest operating system as a virtual disk file on a VMFS volume Virtual mode provides such benefits of
VMFS as advanced file locking for data protection and use of snapshots
Physical compatibility modemdashthis mode provides access to most hardware characteristics of the
mapped device VMkernel passes all SCSI commands to the device with one exception thereby
exposing all the physical characteristics of the underlying hardware In this mode the mapping is done
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
as follows when we create a mapping the configuration stored in a file and that file is stored with the
vm files in datastore This file points to the raw device and makes it accessible to the vm
59 What are RDM Limitations
RDM limitations
There are two types of RDMs virtual compatibility mode RDMs and physical compatibility mode RDMs
Physical mode RDMs in particular have some fairly significant limitations
No VMware snapshots
No VCB support because VCB requires VMware snapshots
No cloning VMs that use physical mode RDMs
No converting VMs that use physical mode RDMs into templates
No migrating VMs with physical mode RDMs if the migration involves copying the disk
No VMotion with physical mode RDMs
Virtual mode RDMs address some of these issues allowing raw LUNs to be treated very much like virtual
disks and enabling functionality like VMotion snapshotting and cloning Virtual mode RDMs are
acceptable in most cases where RDMs are required For example virtual mode RDMs can be used in
virtual-to-virtual cluster across physical hosts Note that physical-to-virtual clusters across boxes
though require physical mode RDMs
While virtual disks will work for the large majority of applications and workloads in a VI environment
the use of RDMs--either virtual mode RDMs or physical mode RDMs--can help eliminate potential
compatibility issues or allow applications to run virtualized without any loss of functionality
I previously posted some questions related to VMware already And the post has very good
response You can read it here - httpwww2isupportyounet201006vmware-interviewquestions-
tipshtml
Other links on my blog
How to access ESX Server in Different ways What are the major differences in
these
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
8 of 10 232012 713 AM
Virtual Center Centralized Administration of Virtual Infrastructure
VMWare Interview Questions amp Tips ndash Part -I
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
How to fix HA errors in VMware ESX Server
How to install Virtual Center 25 vCenter 40 in a simple steps
Unable to power on the Virtual Machine How to fix it
What is vMotion How it Happens
What is VMware Consolidated Backup and How it is used
Virtualization Basics
VMware ndash Virtual Networking
VMware ESX Server Virtualization Expert
Virtual Machine Provisioning
How to access ESX Server in Different ways What are the major differences in
these
Virtual Center Centralized Administration of Virtual Infrastructure
VMware Workstation A Virtual Friend
How to Setup VMware Infrastructure using VMware Workstation
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
9 of 10 232012 713 AM
VMware Storage A Place to store VMrsquos
VMFS Virtual Machine File System
VMware Storage How to configure Datastores using FC SAN
Question ESX installation inside VMware workstation problems
Openfiler Opensource iSCSI SAN Server
VMware Storage Configuration Using iSCSI SAN
VMware Storage RDM Raw Device Mappings
vSphere Completeness of Virtualization
vSphere PowerCLI Getting Started
VMware Storage NFS Datastores
Published by Google Docs ndash Report Abuse ndash Updated automatically every 5 minutes
VMware_Interview_Questionsdoc httpsdocsgooglecomdocumentpubid=1xpi2Mg3iiZ3IqkhOP5BwiG
10 of 10 232012 713 AM
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Please come to my blog to acess the samehttpwww2isupportyounet
Some Important Points About VMWare
1 VMWare Kernel is a Propriotory Kenral and is not based on any of the UNIX ope
rating systems its a kernel developed by VMWare Company
2 The VMKernel cant boot it by itself so that it takes the help of the 3rd pa
rty operating system In VMWare case the kernel is booted by RedHat Linux operat
ing system which is known as service console
3 The service console is developed based up on Redhat Linux Operating system i
t is used to manage the VMKernel
4 To restart webaccess service on vmware
service vmware-webaccess restart
5 To restart ssh service on vmware
service sshd restart
6 To restart host agent on vmware esx server
service vmware-hostd restart
7 Path for the struts-configxml
usrlibvmwarewebAccesstomcatapache-tomcat-5517webappsuiWEB-INF
8 To start the scripted install the command is
esx ks=nfs111222333444dataKSconfig ksdevice=eth0
location device name
9 Virtual Network in Simple
Virtual Nic(s) on Virtual Machine(s) -----gt Physical Nic on the ESX Server (V
irtual Switch - 56 Ports) ------gt Physical Switch Port
with Different VLANS
should be tr
unked with all the VLANS to which the VMs need access
All the ESX servers should be configured with Same number of Physical Nics (v
Switches) and Connectivity also should be same So that vMotion succeeds
All the Virtual Machines are connected to one vSwitch with Different VLANS t
his means the Physical Nic(vSwitch) needs to be trunked with the same VLANS on t
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
he Physical Switch Port
10 What are the three port groups present in ESX server networking
1 Virtual Machine Port Group - Used for Virtual Machine NEtwork
2 Service Console Port Group - Used for Service Console Communications
3 VMKernel Port Group - Used for VMotion iSCSI NFS Communications
11 What is the use of a Port Group
The port group segregates the type of communication
12 What are the type of communications which requires an IP address for sure
Service Console and VMKernel (VMotion and iSCSI) these communications does n
ot happen without an ip address (Whether it is a single or dedicated)
13 In the ESX Server licensing features VMotion License is showing as Not used
why
Even though the license box is selected it shows as License Not Used unti
l you enable the VMotion option for specific vSwitch
14 How the Virtual Machine Port group communication works
All the vms which are configured in VM Port Group are able to connect to t
he physical machines on the network So this port group enables communication be
tween vSwitch and pSwitch to connect vms to pms
15 What is a VLAN
A VLAN is a logical configuration on the switch port to segment the IP Traf
fic For this to happen the port must be trunked with the correct VLAN ID
16 Does the vSwitches support VLAN Tagging Why
Yes The vSwitches support VLAN Tagging otherwise if the virtual machines
in an esx host are connected to different VLANS we need to install a separate p
hysical nic (vSwitch) for every VLAN That is the reason vmware included the VLA
N tagging for vSwitches So every vSwitch supports upto 1016 ports and B
TW they can support 1016 VLANS if needed
17 What is Promiscuous Mode on vSwitch What happens if it sets to Accept
If the promiscuous mode set to Accept all the communication is visible to
all the virtual machines in other words all the packets are sent to all the por
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
ts on vSwitch
If the promiscuous mode set to Reject the packets are sent to inteded port
so that the intended virtual machine was able to see the communication
18 What is MAC address Changes What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow incoming
traffic to the VM So by setting Reject Option both MAC addresses will be re
mains same and the incoming traffic will be allowed to the VM
19 What is Forged Tranmits What happens if it is set to Accept
When we create a virtual machine the configuration wizrd generates a MAC ad
dress for that machine you can see it in the vmx (VM Config) file If it doesn
t matches with the MAC address in the OS this setting does not allow outgoing
traffic from the VM So by setting Reject Option both MAC addresses w
ill be remains same and the outgoing traffic will be allowed from the VM
20 What are the core services of VC
VM provisioing Task Scheduling and Event Logging
21 Can we do vMotion between two datacenters If possible how it will be
Yes we can do vMotion between two datacenters but the mandatory requiremen
t is the VM should be powerd off
22 What is VC agent and what service it is corresponded to What are the minim
um reqs for VC agent installation
VC agent is an agent installed on ESX server which enables communication be
tween VC and ESX server
The daemon associated with it is called vmware-hostd and the service whi
ch corresponds to it is called as mgmt-vmware in the event of VC agent failure
just restart the service by typing the following command at the service console
service mgmt-vmware restart
VC agent installed on the ESX server when we add it to the VC so at the ti
me of installtion if you are getting an error like VC Agent service failed to
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
install check the Opt size whether it is sufficient or not
23 How can you edit VI Client Settings and VC Server Settings
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configurati
on to Change VC Settings
24 What are the files that make a Virtual Machine
vmx - Virtual Machine Configuration File
nvram - Virtual Machine BIOS
vmdk - Virtual Machine Disk file
vswp - Virtual Machine Swap File
vmsd - Virtual MAchine Snapshot Database
vmsn - Virtual Machine Snapshot file
vmss - Virtual Machine Suspended State file
vmwarelog - Current Log File
vmware-log - Old Log file
25 What are the devices that can be added while the virtual Machine running
Only HardDisk
26 How to set the time delay for BIOS screen for a Virtual Machine
RC on VM select edit settings choose options tab and select boot option
set the delay how much you want
27 What is a template
We can convert a Vm into Template and it cannot be powered on once its cha
nged to template This is used to quick provisioning of VMs
23 What to do to customize the windows virtual machine clone
copy the sysprep files to Virtual center directory on the server so that t
he wizrd will take the advantage of it
24 What to do to customize the linuxunix virtual machine clone
VC itself includes the customization tools as these operating systems are
avaialble as opensource
25 Does cloning from template happens between two datacenters
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Yes it can if the template in one datacenter we can deploy the vm from
that template in another datacenter without any problem
26 What are the common issues with snapshots What stops from taking a snapshot
and how to fix it
If you configure the VM with Mapped LUNs then the snapshot failed If it
is mapped as virtual then we can take a snapshot of it
If you configure the VM with Mapped LUNs as physical you need to remove i
t to take a snapshot
27 What are the settings that are taken into to consideration when we initiate
a snapshot
Virtual Machine Configuration (What hardware is attached to it)
State of the Virtual Machine Hard Disk file ( To revert back if needed)
State of the Virtual Machine Memory (if it is powered on)
28 What are the requirements for Converting a Physical machine to VM
An agent needs to be installed on the Physical machine
VI client needs to be installed with Converter Plugin
A server to importexport virtual machines
29 What is VMWare consolidated backup
It is a backup framework that supports 3rd party utilities to take backups
of ESX servers and Virtual Machines Its not a backup service
30 To open the guided consolidation tool what are the user requirements
The user must be member of administator
The user should have Logon as service previlages - To give a user these p
revilages open local sec policy select Logon as service policy and add the use
r
The user should have read access to AD to send queries
31 How to restart firewall on ESX server
service firewall restart
32 What are the pre-requisites for VMWare Update Manager
Allow the Update Manager Clent in the Firewall
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
If you get metadata patch is missing error go to UpdateManager directory o
n C drive find the sub-directories for the updates are created or not To fix th
is Click on plugins menu Select Update manager and then Schedule Update Downloa
d this will download the updates to the directories
Add a Baseline to ESX server or Virtual Machine detect the updates
Put the host in maintanance mode to install the updates it is mandatory fo
r ESX server
33 What is the mandatory req for HA to work properly
DNS should be setup properly to enable communication between hosts in a clu
ster
34 How to set ESX Host into maintenance mode from Service console
Posted by Preetam Zare on August 24 2007
Below is the command which you will have to execute from SVC Console to enter ho
st into maintenance mode
vimsh -n -e hostsvcmaintenance_mode_enter
To exit maintenance mode
vimsh -n -e hostsvcmaintenance_mode_exit
Now next question is how I check whether host is in maintenance modeHere is it1048576
vimsh -n -e hostsvcruntimeinfo 1048576 grep inMaintenanceMode 1048576 awk 1048576print $31048576
httpwwwvmadmincoukvmware35-esxserver54-virtualswitchescmd
VMWare Top Interview Questions with Answers
1) Explain about your production environment How many clusterrsquos ESX Data Centers Hw etc
2) How does VMotion works Whatrsquos the port number used for it
ANS--gt TCP port 8000
3) Prerequisites for VMotion
Ans--gt
1)ESX Servers must be configured with VMkenerl ports enabled for vmotion and on the same
network segment
2)ESX Servers must be managed by the same Virtual Center server
3)ESX Must have compatible CPUs
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
4)ESX Servers muct have consisten Networks and NEtwroks labels
5)The VMs must be stored on shared storage - iSCSI or FC SAN or NASNFS
6)The VMs can not use localcdfloppy or internal only vrtual switches on the ESX server
Check out httpwwwvmwarecompdfvi3_35esx_3r35u2vi3_35_25_u2_admin_guidepdf for
more information
4) How does HA works Port number How many host failure allowed and why
ANS--gt Maximum allowed host failures within a HA cluster is 4 What happens if 4 hosts have failed
and a 5th one also fails
I have still enough free resources to start up the virtual machines on the remaining hosts Will HA
start these virtual machines from the 5th failed host on the remaining hosts
ANS) That depends If you have admission control enabled if there are any resource constraints
some VMs may not restart If you have admission control disabled the VMs will get restarted on
any host left in the cluster However that doesnt mean they will be functional Make sure you
have enough port groups configured on your vSwitch for your Virtual Machine port group to
accommodate
Host Firewalls On ESXESXi hosts VMware HA needs and automatically opens the following
firewall ports
Incoming port TCPUDP 8042-8045
Outgoing port TCPUDP 2050-2250
5) What are active host primary host in HA Explain it
ANS--gt
When you add a host to a VMware HA cluster an agent is uploaded to the host and configured to
communicate
with other agents in the cluster The first five hosts added to the cluster are designated as primary
hosts and
all subsequent hosts are designated as secondary hosts The primary hosts maintain and replicate
all cluster
state and are used to initiate failover actions If a primary host is removed from the cluster
VMware HA
promotes another host to primary status
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Any host that joins the cluster must communicate with an existing primary host to complete its
configuration
(except when you are adding the first host to the cluster) At least one primary host must be
functional for
VMware HA to operate correctly If all primary hosts are unavailable (not responding) no hosts can
be
successfully configured for VMware HA
One of the primary hosts is also designated as the active primary host and its responsibilities
include
n Deciding where to restart virtual machines
n Keeping track of failed restart attempts
n Determining when it is appropriate to keep trying to restart a virtual machine
If the active primary host fails another primary host replaces it
6) Prerequisites for HA
First for clusters enabled for VMware HA all virtual machines and their configuration files must
reside on shared storage (Fibre Channel SAN iSCSI SAN or SAN iSCI NAS) because you need to
be able to power on the virtual machine on any host in the cluster
Second VMware HA monitors heartbeat between hosts on the console network for failure
detection So to have reliable failure detection for HA clusters the console network should have
redundant network paths That way if a hosts first network connection fails the second
connection can broadcast heartbeats to other hosts
Last if you want to use DRS with HA for load balancing the hosts in your cluster must be part of
a VMotion network If the hosts are not in the VMotion network however DRS can still make
initial placement recommendations
7) How do DRS works Which technology used What are the priority counts to migrate the VMrsquos
8) How does snap shotrsquos works
9) What are the files will be created while creating a VM and after powering on the VM
10) If the VMDK header file corrupt what will happen How do you troubleshoot
11) Prerequisites VC Update manager
12) Have you ever patched the ESX host What are the steps involved in that
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
13) Have you ever installed an ESX host What are the pre and post conversion steps involved in
that What would be the portions listed What would be the max size of it
14) I turned on Maintenance mode in an ESX host all the VMrsquos has been migrated to another host
but only one VM failed to migrate What are the possible reasons
15) How will you turn start stop a VM through command prompt
16) I have upgraded a VM from 4 to 8 GB RAM itrsquos getting failed at 90 of powering on How do
you troubleshoot
17) Storage team provided the new LUN ID to you How will you configure the LUN in VC What
would be the block size (say for 500 GB volume size)
18) I want to add a new VLAN to the production network What are the steps involved in that And
how do you enable it
19) Explain about VCB What it the minimum priority () to consolidate a machine
20) How VDR works
21) Whatrsquos the difference between Top and ESXTOP command
22) How will you check the network bandwidth utilization in an ESXS host through command
prompt
23) How will you generate a report for list of ESX VMrsquos RAM and CPU used in your Vsphere
environment
24) What the difference between connecting the ESX host through VC and Vsphere What are the
services involved in that What are the port numbersrsquos used
25) How does FT works Prerequisites Port used
26) Can I VMotion between 2 different data centers Why
27) Can I deploy a VM by template in different data centers
28) I want to increase the system partition size (windows 2003 server- Guest OS) of a VM How will
you do it without any interruption to the end user
29) Which port number used while 2 ESX transfer the data in between
30) Unable to connect to a VC through Vsphere client What could be the reason How do you
troubleshoot
31) Have you ever upgraded the ESX 35 to 40 How did you do it
32) What are the Vsphere 40 VC 40 ESX 40 VM 70 special features
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
33) What is AAM Where is it used How do you start or stop through command prompt
ANS) VMware-aam = HA
VMware purchased the HA technology from Legato who originally coined it as Automated
Availability Manager
34) Have you ever called VMWare support Etc
35) Explain about Vsphere Licensing License server
36) How will you change the service console IP
Note ESX 40 Update 2 introduces a new tool that simplifies the process of creating or restoring
networking in the ESX service console For more information see Configuring or restoring
networking from the ESX service console using console-setup (1022078)
Changing settings from the physical or remote console connection
Changing the IP for the Service Console must be done from the physical console or through a
remote console session If you make changes through a network connection such as SSH network
connectivity to the Service Console disconnects because the Service Consoles network interface
changes
1Run this command to set the IP address
[rootserver root] esxcfg-vswif -i -n vswif0
where is the IP address and is the subnet mask
Note In this example vswif0 is the Service Console adapter that is the interface to which you are
applying the IP address change
2Open the etchosts file with a text editor and modify it so that it reflects the correct IP
address and hostname
3To change the default gateway address and the hostname edit the etcsysconfignetwork file
and change the GATEWAY and HOSTNAME parameters to the proper values
4For the changes to take place restart the network service with the command
[rootserver root] service network restart
Note If you are required to edit the hostname then you must reboot the host
Note This command breaks any current network connections to the Service Console but virtual
machines continue to have network connection If the ESX host is managed by VirtualCenter or
vCenter Server you may have to remove and re-add the host to the inventory For more
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
information see ESX not working properly in VirtualCenter after IP address change (1005633)
Note Making changes to IP and DNS server settings can have a negative impact on the normal
operation of ESXESXi particularly in HA clustered environments For more information see
Identifying issues with and setting up name resolution on ESXESXi Server (1003735)
Note If the changed IP does not persist across a reboot try deleting and recreating the Service
Console vswif management interface For more information see Recreating Service Console
networking from the command line (1000266)
Changing the hostname without rebooting
To dynamically change the hostname run the command
[rootserver root] hostname newname
Note This command creates a temporary hostname change This change is lost when the system is
rebooted
Changing the DNS server settings
To change the DNS server settings update the nameserver IPs and search domain in the
etcresolvconf file
Changing settings in VMware vSphere or Infrastructure Client
To change the hostname domain DNS servers and default gateway in VMware vSphere or
Infrastructure Client
1Highlight the ESX host and click the Configuration tab
2Click DNS and Routing
3Click Properties
4To change the hostname domain and DNS servers click the DNS Configuration tab and enter
the appropriate values
Note Disable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change
5To change the default gateway click the Routing tab and enter the appropriate value
6Reboot the ESX host for the changes to take effect
7Reconnect the ESX host to vCenter Server with the new IP address
Generating new certificates for the ESX host
The ESX host generates certificates the first time the system is started Under certain
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
circumstances it might be required to force the host to generate new certificates Typically new
certificates only need to be generated if the hostname has been changed or the certificates have
been deleted accidentally
Each time you restart the vmware-hostd process the mgmt-vmware script searches for existing
certificate files ( ruicrt and ruikey) If the files cannot be found new certificate files are
generated
To generate new certificates
1Put the host into Maintenance Mode
2In the directory etcvmwaressl back up any existing certificates by renaming them with these
commands
[rootserver root] mv etcvmwaresslruicrt etcvmwaresslorigruicrt
[rootserver root] mv etcvmwaresslruikey etcvmwaresslorigruikey
Note If you are regenerating certificates because you accidentally deleted them you do not have
to rename them
3Reboot your host to allow it to begin using the new certificate or restart the host services
aRestart hostd using this command
service mgmt-vmware restart
bRestart vmkauthd using this command
service vmware-vmkauthd restart
4Exit Maintenance Mode
5Confirm that the ESX host successfully generated new certificates by running this command and
comparing the time stamps of the new certificate files with origruicrt and origruikey
[rootserver root] ls -la etcvmwaresslrui
Notes
bullDisable VMware High Availability if you do not want virtual machines to failover during the
hostname IP change If you are using vSphere 4x you can just disable host monitoring in the HA
settings
bullFor related information see Verifying ESX Server host networking configuration on the service
console (1003796)
bullYou may be required to regenerate your SSL certificate For more information see Replacing or
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Regenerating an SSL Certificate for the Management Interface (1843)
bullYou are required to edit files on an ESX host For more information see Editing files on an ESX
host using vi or nano (1020302)
bullFor information on replacing VirtualCenter Server ceritificates see
Replacing VirtualCenter Server Certificates in Virtual Infrastructure 3
Replacing VirtualCenter Server Certificates in vSphere 4
bullThe iSCSI Qualified Name used for iSCSI storage configuration is based on the hostname of the
ESX host If you change the hostname of the ESX host ensure to review your iSCSI software
initiator configuration For more information on iSCSI troubleshooting see Configuring and
troubleshooting basic software iSCSI setup (1008083)
bullFor more information on changing the hostname see Changing the name of an ESX host
(1010821)
37) Whatrsquos the difference between ESX and ESXi
38) Whatrsquos the difference between ESX 35 and ESX 40
39) P2V Prt Number and Log file location
TCPIP Ports Required by VMware Converter
Table lists the ports Converter uses in the conversion process
If your VirtualCenter Servers or ESX Servers are configured to listen on port 905 you will have to
make
adjustments accordingly
Communication Paths | Port
Converter application to remote physical machine | 445 and 139
Converter application to VirtualCenter Server | 902
Converter application to ESX Server 3x | 902
Physical machine to VirtualCenter Server | 902
Physical machine to ESX Server 3x | 902
Log File Locations
UFAD logs
WINDIRTempvmware-tempvmware-converter
WINDIRvmware-tempvmware-converter (in Windows NT)
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Client logs
TEMPvmware-tempvmware-client
Send these in to support using File gt Export Logs For Converter Boot CD map a network drive
using the
network configuration tool (see Chapter 5 ldquoUsing the Converter Boot CD for Local Cold Cloningrdquo
on page 37)
and use File gt Export Logs
40) Micro vMotion
41)
-------------------------------------------------------------------------------------------------------------------------
----------------------------------------------
Q How is VMware more stable than say a new physical server
A The idealized hardware provided by VMware provides a consistent virtual hardware
environment that increases that stability of your virtual machines independent of the underlying
physical hardware
Q Is any installation method better than any other
A No Whichever installation method youre comfortable with and that produces a good build is
the one for you
Q Im having problems with my installation What should I do
A Ensure that the hardware youre loading ESX Server on is supported The same goes for the
configuration If you are certain the hardware and configuration are supported then run the vmsupport
script mentioned previously
Q Why does this chapter include only the graphical installer method
A Its the recommended installation method from VMware and one that many in the x86-world are
the most comfortable with If you wish to try it another way VMware offers a very complete
installation document covering the various installation methodologies
Q When I copy my virtual machine and try to run it on my network I get hostname already exists
and IP address already exists errors I thought I could simply copy my virtual machine What is the
problem
A You can copy your virtual machine which is why youre running into this problem The copy is
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
an exact copy Thus you need to change the hostname IP address and even the computers SID (if
it has one)
Q Can I move my Gold Master to my other ESX Servers
A Yes its a recommended time-saver If your ESX Servers share a LUN that too is a way to access
your Gold Master or your VMlibrary for that matter
Q Are there any limitations to the number of virtual machines I can run on my ESX Server
A Yes Each ESX Server allows for only 80 virtual CPUs and 200 registered virtual machines
Q Can I take a virtual machine running on VMware Workstation or GSX and run it in ESX
A It depends The process is not as simple as cutting and pasting There is a specific import
process required for migrating virtual machines from either Workstation or GSX into ESX Access
the following link for the exact instructions httpwwwvmwarecompdfmobility_guidepdf
Q Do you need to tweak the settings of your virtual machines after youve built them
A No VMware has configured the defaults of your build to suit most server loads However
depending on the profile of your server and the resource intensiveness of the service its providing
you may want to consider tweaking some of the default settings to better ensure service stability
and reliability
Q Are there more advanced features than the ones detailed in this chapter
A Yeshellip a lot more
Q Is clustering more stable in VMware
A We find that the idealized hardware in combination with VMwares improvements in clustering
support has made virtual clustering very stable
Q Can you Vmotion a cluster
A That depends on the cluster type and how it is configured Clusters using Raw Device Mapping
in virtual mode can be moved with Vmotion according to VMware documentation
Q Does VMware support NIC teaming
A Yes and its a very good idea to configure your ESX Server especially if its for production with
teamed NICs This will provide hardware fault tolerance in case one NIC fails
Q How many physical NICs do I need on my ESX Server
A That depends on the number of virtual machines and the network traffic they produce You
should have a minimum of two one for your Service Console and one dedicated to your virtual
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
machines
Q If Im building a cluster using Microsoft Clustering Service whats the best configuration for my
heartbeat NIC
AFor a Cluster in a Box create a VMnet that your nodes of your cluster can attach their heartbeat
NICs
Q Can you attach virtual machines on any ESX Server to a VMnet
A No Only virtual machines on the ESX Server that the VMnet resides can attach to it
Q Why should you pay for a p-to-v toll when there are a number of ways to do it for free
A If you dont have the time or inclination to learn the manual process or need the assurance of a
vendor for your physical-to-virtual migrations then a tool that comes with support is a very
reasonable option
Q What takes the longest in the p-to-v process
A Transferring the data of the physical server into either an image file or the virtual server itself
Thats why tweaking your network settings for optimal throughput is essential when p-to-ving a
server
Q Can you create complete backups of your physical servers and then recover them into virtuals
A Ive used NTBackup to back up Windows 2000 Professional and Windows XP and created virtuals
out of bkf files It works but theres a bit of futzing around with the virtual once it is running Try
it
Q Whats the most essential part of creating a smooth migration plan
A Practice No matter what the tool or process practice it and learn its gotchas and the
workarounds No matter what method you use there will be times when it wont go as planned
Practicing your p-to-v process on a number of physical platforms and disk configurations allows
you to become more adept once youre doing it for real
Q Will my software vendor support my application in a VMware environment
A Youll need to contact your specific software or applications vendor to find out however an
increasing number of software vendors support virtualized environments Once youve migrated
your application from a physical to virtual environment its very easy to migrate back to a physical
environment for vendor support An excellent document provided by VMware can be found at the
following link wwwvmwarecompdfms_support_statementpdf
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
Q What are the best enablers to help ensure our server consolidation is a success
A Engaging with the lines of business and application owners not only assists in attaining an
actionable schedule but also develops a highly collaborative environment that facilitates buy-in
and support for your project In addition it will be difficult to incorporate rationalization into your
project unless you are working directly with the business or application owners
Q What tools do you recommend for a server consolidation or virtualization project
A Its imperative to have a robust and comprehensive tool for capacity planning including
historical data This tool can be utilized in every phase of your project Other tools to support the
project include modeling tools used in test consolidation scenarios Finally youll need to evaluate
and document tools and processes for each technology you wish to consolidate The migration
tools will need to support all the platforms you wish to use in your migration scenarios
Q What is the VMlibrary
A The VMlibrary (vmlib) is simply a directory on your ESX Server that lets you organize the tools
and files you need to manage and maintain your virtual infrastructure
Q Can ISOs be shared between ESX Servers
A If you place your VMlibrary on a LUN thats shared amongst your ESX Servers you can share your
ISO images or anything else you place in your VMlibrary
Q Why is Vmotion so cool
A Try ithellipand then imagine the possibilities and applications Youll be a convert soon enough
Q You mentioned that additional ISVs were creating management capabilities for virtual
infrastructures in their products Which ones
A Look at HP Insight Manager Dell OpenManage IBM Director BMCs Patrol product line Computer
Associates Unicenter and many others
Q I cant add a new virtual hard drive to my virtual machine What should I do
A You may not have the appropriate permissions to add virtual hardware to the VM or the VM
may be powered on and wont allow the addition of virtual hardware while powered on
Q I just created a new virtual machine and attached to an existing disk Every time I power on
the VM I get a blue screen What could the problem be
A Make sure the OS type that you selected when you created the VM matches the OS type
installed on the virtual disk For example if you selected Windows 2003 Standard for the VM when
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
you created it but the existing virtual disk has Windows 2000 Standard installed youll probably
encounter issues
Q I followed the directions for Active Directory authentication and I still cant log in using an
account and password in AD What should I do
A Check the time on your ESX Server and Active Directory and make sure theyre synced up
Kerberos is very sensitive to being out of sync and could reject credentials if the time is not within
specific limits You can also review the System event logs for clues
Q What is the most important aspect of deploying ESX Server and virtual machines
A The ability to provide service at least as good as that which you had with physical servers With
adherence to best practices you should easily be able to provide this and exceed it by a
phenomenal degree
Q ISOs have been mentioned in several of the chapters Why are they so important
A Good administrators strive to never leave their chairs cubes or offices If they do they may
just run into a user (were kidding of course) Having a library of ISOs can help you in this
endeavor In addition they run a lot faster than regular CDs
Q What will happen if I deploy systems management software on the ESX Server itself
A If youre going to do this make sure you allocate enough memory so that the application doesnt
impact the performance of your ESX Server and thus your virtual machines Also use a system
management package that is supported and test your installation on your ESX Server thoroughly If
you notice a degradation of performance contact the systems management software vendor The
major vendors have instructions and best practices for deploying their products onto ESX Server
Q What is the most important best practice to follow
A The one that ensures your smooth evolution into a virtual infrastructure education Learn every
aspect of a virtual environment to the best of your ability Be passionate about it and youll reap
the rewards See the recommended reading list troll the VMware Web site regularly as well as
other Web sites dedicated to virtualization such as p2vnet vmgurucom and virtualstrategy
com
Q Which version of VMware ESX Server supports Boot from SAN
A ESX Server 25 supports Boot from SAN but has the following limitations ESX server had to be
installed in boot from SAN mode the HBA can only be used by the Service Console LUN masking
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
should be used to restrict other ESX servers from the boot LUN the HBA of the boot LUN must be a
QLogic HBA and the boot LUN must be the lowest numbered LUN controlled by the storage
processor
Q Where are log files for VMware ESX Server written to
A varlogsvmware
Q What do you do if you forget the root password of the Service Console
A You will need to boot into single-user mode from the Service Console by selecting linux from
the LILO boot menu and appending -s to your boot choice This will boot the console into singleuser
mode and will allow you to use the passwd command to change the root user password
Q Why do I still see processes for my virtual machine when running the ps command on the
Service Console even though my virtual machine is powered down
A If there is still a virtual console session running for your VM you will still see processes
associated with it for mouse keyboard and screen (MKS) even though it is powered off
Q I accidently unmounted the VMFS volume on my ESX Server How can I re-mount the volume
without re-booting
A You can type mount t vmfs vmfs vmfs
Q What software is qualified for use with VMware 251
A Please see httpvmwarecompdfesx_backup_guidepdf for an up-to-date list of software
thats compatible with ESX
Q What SANs are compatible with ESX Server
A Please see httpvmwarecompdfesx_SAN_guidepdf for details on ESX-to-SAN server
compatibility
Q What are the certified backup tools for ESX
A Please see httpvmwarecomsupportesx25docbackup_tools_linkshtml
Q Can I back up my entire virtual machine from the Service Console
A Yes but it is not advised The console services should be left alone to manage the entire virtual
machine infrastructure Its best that backups be performed by separating the applications and
data from the operating systems because backups can become quite large very quickly You should
consider a backup of the environments that change frequently (data and applications) with an
agent specifically designed to perform this function A backup of those virtual disks that change
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
infrequently and need VMFS formats should be backed up from the Service Console These
console-based backups should be performed in a powered-down or suspended approach
(preferred) or a suspended environment using redo logs as an alternative All backups performed
from a systems console mode must be restored in an all-or-nothing approach Recovery for a single
file or directory can only be accomplished via a backup agent or from a backup to a SAN
environment using a variety of different recoveryrestoral techniques
Q Im not able to connect to the Service Console over the network What could the issue be
A You may have allocated the Service Console NIC to the VMkernel Use vmkpcidivyi to reassign
the NIC to the Service Console
Q I have a virtual machine that did not start up correctly but now I cant power it down from the
MUI or Virtual Center How can I get this VM to shut down
A You can use the vmware-cmd utility to force a hard power down The following syntax should
work
vmware-cmd path-to-vmvm-directoryvmvmx stop hard
Q I find using commands to be very difficult Why cant I use X Windows on the Service Console
A You actually could run the X Windows system on the Service Console but it will eat up valuable
resources that are needed by the system to manage all the processes related to Virtualization
VMware specifically says not to run X Windows on the Service Console So its best to just buck up
and deal with it
Q Is there a way to mount the vmfs volumes if they accidentally get unmounted without having to
reboot
A Yes You can run mountt vmfs vmfs vmfs
Q How do I check the speed and duplex setting of the Service Console NIC Also how do I change
it if needed
A Youll need to cat out the eth0info file for your type of adapter This file can be found at
procnettype-of-niceth0info To give you an example our server has an Intel Pro 100 Nic for
the Service Console so for us to find the speed and duplex information we would type cat
procnetPRO_LAN_Adapterseth0info
Q How long has Xen been around
A Since 2004 and theyre located in Palo Alto California Hmmhellipwhat other virtualization
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical
company is in Palo Alto
Q What is a hypervisor
A In VMware parlance its the virtualization layer
Q Why did VMware limit its beta of ESX Server 30 to so few
A Good questionhellipWe dont know and we hope that VMwares future beta programs are opened up
to a larger audience
Q If I cant get a SAN will local storage with a RAID device be sufficient
A Absolutely You wont get some of the cooler tools like VMotion but being virtual on local
storage is better than remaining physical