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Amit Agarwal Date – 18th July, 2016

Virtualization -101 A Deep Dive

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About Me

• 4 years of experience working with Virtualization Products.

• VMware Certified Associate and Professional – DataCenter Virtualization.

• Contributor to the book – Mastering vSphere PowerCLI.

• Active member of VMware Community and VMware user group(VMUGs).

• Working with GSLab for the past 1 year in Cloudgenix Project as Senior QA.

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Agenda

• The basic principles and technology of virtualization

• Anatomy of Hypervisor (ESXi)

• Anatomy of a virtual machine

• vCenter usage and some advance vSphere features

• vNetworking concepts

• A brief on vSphere powerCLI Scripting and Usage

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Virtualization : Basic Building Blocks

• Hypervisor :- Two Types – - BareMetal (ESXi) - Hosted (VMware Workstation, Virtual Box)

• ESXi contains VMkernel which is the 64 bit microkernel that directly handles memory and CPU.

• Hardware access uses modules (drivers) adapted to work with VMkernel.• VMkernel does not run VMs directly, VMM does that.

• Virtual Machine Monitor (VMM) :- It is a process that runs in the VMkernel which virtualizes the guest OS instructions and manages memory.

- The VMM passes storage and network I/O requests to the VMKernel. - There is a VMM for each virtual CPU assigned to the virtual machine.

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Virtualization : Basic Building Blocks

• Rings :- - x86 CPUs provide a range protection levels called Rings in which code can execute. - Ring ‘0’ has the highest level priviledge and is where the operating system kernel normally runs.

• Non-Virtualized Systems – OS runs at Ring 0 and owns the Hardware. Applications run in Ring 3 with less privileges.

• Virtualized Systems – VMM runs at Ring 0 which fools the Guest OS into thinking that they are running in Ring ’0’ – Full Virtualization. Newer CPUs (Intel VT-x) uses a new privilege level called Ring ‘-1’, and puts VMM There which results in better performance.

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• CPU Scheduler :-

- Schedules VMs virtual CPU time on the host physical CPUs. - Scheduling many vCPUs to limited pCPUs can be very challenging , for this VMware uses a proportional-share based algorithm. - Optimizes placement of vCPUs onto different sockets to maximize cache utilization.

• Memory Virtualization :-

- VMkernel manages all VM memory. - It creates a contiguous addressable memory space for the VM, - This memory space has the same properties as the virtual address space presented to the applications by the guest operating system. - This also helps for each VM to run in complete isolation.

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Virtualization : Basic Building Blocks

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Complete ESXi Architecture

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Anatomy of a Virtual Machine

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• Representation of a physical machine by software that has its own set of virtual hardware upon which an OS and Apps can be loaded.

• Its basically a set of discrete files located on the datastore accessible to the ESXi Host.

• When VM is powered on, the host mounts the virtual disk.

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vCenter – What is it?

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VMware vCenter Server is the central point for configuring, provisioning, and managing virtualized IT environments.

vCenter Architecture

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vCenter – Do I really need it?

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• Use vCenter Server to centrally manage your hosts and virtual machines instead of logging directly in to each host.

• It inherits thr group roles from AD, hence provide ease in Access Control.

• Many Advance vSphere features are only supported in vCenter like – - vMotion - High Availability - Fault Tolerance - DRS

• It allows us to use the inventory views to organize inventory objects(Storage, Networks, templates etc) in a meaningful way.

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Advance features – vMotion

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• Source and Destination Host must have :

- Visibility to all storage used by the virtual machine- At least a Gigabit Ethernet network.- Access to the same physical

network.- Compatible CPUs.

Enhanced vMotion lets you migrate without a shared storage and same CPU characteristics.

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Advance features – High Availability (HA)

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• In case of a fail-over the virtual machine gets migrated and is literally restarted on one of the remaining hosts in the cluster.

• vCenter manages this and uses a master-slave architecture.

• Heartbeating is the mechanism used by HA to validate whether a host is alive.

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Nested Virtualization

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• You can expose the Intel VT/AMD V hardware virtualization flags to a guest VM riding on VMware.

• This VM can then host its own VM’s.

• There will be a performance hit.

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FinanceEngineering

Physical Network – Design

Comp 2 Comp 3 Comp 4Comp 1

Physical Switch

Comp 6 Comp 7 Comp 8Comp 5

Physical Switch

FinanceEngineering

Physical Network – with VLAN

Comp 2 Comp 3 Comp 4Comp 1

Physical Switch

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Components in vNetworking

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Components in vNetworking

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• Virtual Network Adapters - vNic – VM’s interface to the network - vmknic – vSphere hypervisor’s interface to network(NFS, vMotion, FT)

• Physical Network Adapter - pNic or vmnic – for communicating with entities outside ESXi host.

• Virtual Switch - vSwitch : forwards packets between vNics, vmknics and pNics.

• Port Group - Group of port sharing the same configuration (e.g vlan)

• Uplinks : connections to physical switches

• NIC team : a group of pNnics connected to the same physical network.

HOST 2 (ESX)HOST 1 (ESX)

Virtual Network and Communication

VM1 VM2 VM4

vSwitch

Physical Switch

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2

1

VM3

1

2

4

3 5

6

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Trunk Trunk

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Physical Switch vs Virtual Switch

Similarities -• Maintains MAC Address tables.• Lookup each frame’s destination MAC upon arrival.• Forward frames to one or more ports.• Avoid unnecessary deliveries.

Differences -• Cannot connect to virtual switch together.• As a result of this they do not require Spanning Tree Protocol.• Forwarding table data is unique to each virtual switch.

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vSphere Distributed Switch - vDS

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• Centrally managed, Datacenter-wide switch• Enhanced network monitoring and troubleshooting (RSPAN &

ERSPAN, SNMPv3.0)• Maintain Network runtime state of VMs as they move across

HOSTs (Network vMotion)• Here we will have:

DV Port Group - offer additional features - administrators can define not just outbound traffic shaping, but inbound traffic shaping as well,

DV Uplink

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Complete Picture - vDS

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An Introduction to vSphere PowerCLI Scripting

• vSphere powerCLI can automate any operation you want in your virtual infrastructure.

• Its tightly integrated with Microsoft PowerShell and has 400 cmdlets.

• Follows a Verb-Noun structure, where Verb : Action and Noun : Object. Ex : Get-VM, Get-VMHost Set-VM

• It uses SOAP APIs for connection hence independent of UI changes.

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www.gslab.comThank you vMuch Go Virtualize...!!