Feature Section: Virtualization in the MainStreaM

DELL POWER SOLUTIONS | August 200758 Reprinted from Dell Power Solutions, August 2007. Copyright © 2007 Dell Inc. All rights reserved.

Server virtualization can provide multiple benefits in

enterprise environments, allowing enterprises to

consolidate servers to help increase resource utili-

zation, use power efficiently, and reduce operating costs.

Enterprises can gain similar advantages in the storage envi-

ronment by consolidating those resources, helping them

simplify management, increase flexibility and allow nondis-

ruptive virtual machine (VM) migrations, and meet service-

level agreements (SLAs).

Choosing appropriate storage software functionality is a

key part of combining a VMware software–based virtualized

environment with consolidated storage. Important factors to

consider include data mobility, flexible quality-of-service

(QoS) functionality, high-availability features, and simplified

management.1

Simplifying management with the EMC Navisphere Task Bar Implementing storage software in a virtualized environment

can seem like a daunting task, and the relative ease of

deploying new VMs along with the variable I/O patterns that

result can make efficient storage management a challenge.

Ease of use, then, becomes a key factor when choosing stor-

age management software in such an environment.

The EMC® FLARE® operating environment includes the

Navisphere® Task Bar, which is designed to increase ease of

use for storage administrators and complement the advan-

tages of VMware and EMC software. Administrators can use

this task bar (freely available to those with EMC service main-

tenance contracts) to perform many common storage man-

agement tasks in significantly fewer steps than they would

otherwise require, including rapidly provisioning as much as

1 TB of storage, using the mirror wizard to help protect data,

and creating a clone backup.

Enhancing data mobility through advanced LUN technologyThe FLARE operating environment for Dell/EMC CX3 UltraScale

series storage can provide high levels of data mobility and

resource flexibility, allowing administrators to deploy new

servers quickly and nondisruptively. Dell/EMC metaLUN and

Virtual LUN technologies are designed to complement these

capabilities, enabling real-time online expansion of logical

units (LUNs) and transparent volume movement, respec-

tively, typically without I/O interruption in hosts running the

VMware ESX Server virtualization platform.

MetaLUNs are created by expanding a single LUN through

concatenation, striping, or both. When VMs require additional

Related Categories:

Dell/EMC storage

EMC

Storage software

Virtualization

VMware

Visit www.dell.com/powersolutions

for the complete category index.

Using Dell/EMC Storage Software in a VMware Virtual Environment

When deploying VMware® virtualization software, choosing storage with complementary software can be critical. The advanced software functionality available with Dell/EMC CX3 UltraScale™ series storage arrays is designed to provide the data mobility and resource flexibility necessary to create an integrated, highly available virtualized information infrastructure.

By AnDRew GIlmAn

1 The features described in this article apply to the Dell/emC CX3 UltraScale series, and may not be available with other Dell/emC storage arrays.

Choosing appropriate storage software func-tionality is a key part of combining a Vmware software–based virtualized environment with consolidated storage.”

59www.dell.com/powersolutionsReprinted from Dell Power Solutions, August 2007. Copyright © 2007 Dell Inc. All rights reserved.

capacity, administrators can easily extend the

VMware Virtual Machine File System (VMFS) using

VMware VirtualCenter and its corresponding LUN

through the intuitive Web browser–based inter-

face of the EMC Navisphere Management Suite.

This real-time LUN expansion also supports the

creation of new VMs (see Figure 1). And because

the added capacity is immediately available and

the functionality is invisible to the host applica-

tion, no reboot is necessary.

MetaLUNs are supported with both VMFS

and raw device mapping (RDM), and can help

administrators make efficient use of their stor-

age resources in VMware software–based envi-

ronments. Using the Logical Volume Manager

available within ESX Server enables VMFS vol-

umes to see the additional storage presented by

the Dell/EMC CX3 UltraScale series storage after

a re-scan at the ESX Server level. For RDM vol-

umes, ESX Server hosts can immediately see the

additional capacity presented by the storage

after a re-scan. Administrators can also use

striped metaLUNs to help balance loads across

multiple disks for applications requiring addi-

tional disk space and increased performance.

Because the ESX Server Logical Volume Manager

only supports LUN concatenation, administra-

tors can stripe the LUNs at the array level to help

distribute the I/O load across multiple disks.

Virtual LUN technology is designed to let

enterprises easily manage and alter their

system configuration as their virtualized envi-

ronment grows and changes. The Dell/EMC CX3

UltraScale series allows administrators to mix

a wide variety of drive types—including Serial

ATA (SATA) and both 2 Gbps and 4 Gbps Fibre

Channel—within a single storage system,

complementing virtualization’s inherent flexi-

bility. Virtual LUN technology, available without

additional licensing fees, enables administra-

tors to create tiers of VMs using these different

drive types, migrate VMs between tiers, and

alter the VM file system’s performance charac-

teristics at the LUN level, all without taking the

system offline or disrupting the VMs. If specific

VMs become more critical than they were previ-

ously, administrators can use Virtual LUNs to

easily migrate their data from SATA to Fibre

Channel storage to help increase performance

(see Figure 2).

Meeting SLAs with EMC Navisphere Quality of Service Manager The relative ease of deploying VMs brings its own

challenges, such as VM performance prioritiza-

tion. Because different VMs require different

service levels, in complex virtualized environ-

ments it can be paramount to choose storage

that provides complementary QoS functionality,

allowing administrators to choose which VMs

can access additional storage resources during

periods of system contention. Moreover, this

storage must be able to meet specific perfor-

mance thresholds during these periods.

The Dell/EMC Navisphere Quality of Service

Manager (NQM) application, accessible through

the Navisphere Web browser–based interface,

provides granular management to help meet

LUN SLAs in VMware software–based environ-

ments. NQM uses a data feedback loop to

Vm Vm Vm

Vmware eSX Server system

Dell/emC storage

FibreChannel

FibreChannel

Vm Vm Vm Vm Vm Vm

Vmware eSX Server system

Dell/emC storage

FibreChannel

FibreChannel

FibreChannel

FibreChannel

Dell/emC metalUn technology

Figure 1. Performing real-time LUN expansion to accommodate additional virtual machines with Dell/EMC metaLUN technology

Vm Vm Vm Vm Vm Vm

Vmware eSX Server system

Dell/emC storage

FibreChannel

FibreChannel

Vm Vm Vm Vm Vm Vm

Vmware eSX Server system

Dell/emC storage

FibreChannel

FibreChannel

FibreChannel

FibreChannel

Dell/emC Virtual lUn technology

SATA SATA SATA SATA SATA SATA

Figure 2. Migrating LUNs to a high-performance tier with Dell/EMC Virtual LUN technology

Reprinted from Dell Power Solutions, August 2007. Copyright © 2007 Dell Inc. All rights reserved.

measure VM performance based on predefined

performance objectives. Depending on the

application performance profile, administrators

can use three metrics within NQM to determine

the service level of a specified VM: throughput,

bandwidth, and response time. After identify-

ing the appropriate service-level metric(s), they

can then choose one of two control methods:

goals or limits.

NQM also includes a scheduling capability

allowing different policies to be used at differ-

ent times. For example, administrators could

configure NQM to provide their e-mail applica-

tion with full system resources during normal

operating hours, then limit the resources avail-

able to that application during the evening

when a backup application is running.

Administrators can easily use the metrics and

scheduling capabilities of NQM to dynamically

manage service levels based on enterprise

requirements and help ensure that, for exam-

ple, I/O processor–intensive operations such

as VM creation do not affect production VM

performance.

For VMs running applications that require

specific service levels, administrators typically

should configure a dedicated LUN as a VMFS

or RDM volume that is presented only to that

VM, which helps ensure that the VM receives

the appropriate throughput, bandwidth, and

response time. Alternatively, they can place

VMs requiring specific service levels on a

single LUN and use NQM to set a service-level

goal for all of the VMs on that LUN.

Combining NQM with the VMware

Distributed Resource Scheduler (DRS) feature,

which provides service-level management for

VM virtual processors and memory, can enhance

QoS management capabilities. DRS monitors

utilization across resource pools and dynami-

cally allocates resources among VMs based on

predefined policies, and can make additional

resources available by migrating live VMs to

different physical hosts using VMware VMotion™

technology. When combined, NQM and DRS can

provide comprehensive policy-based service-

level management for applications throughout

a data center.

Deploying highly available storage with Dell/EMC UltraPoint architecture Even in virtualized environments, an application’s

availability is only as good as the storage its data

resides on. Dell/EMC CX3 UltraScale series arrays

are designed to provide cost-effective mid-range

storage with industry-leading high-availability

capabilities. Architecture, process, and soft-

ware enhancements over previous-generation

Dell/EMC storage enable these arrays to provide

enterprise-class reliability to VMware software–

based environments.

The Dell/EMC CX3 UltraPoint DAE3P enclo-

sure offers a back end designed to increase fault

isolation by using a point-to-point architecture

rather than an arbitrated loop between the link

controller card and the disk drives. Isolating the

disk drives when a fault is detected or when the

drives are being installed mitigates risks to

system-wide availability.

Complementing the increased resiliency of

the UltraPoint hardware architecture are recent

enhancements to the FLARE operating environ-

ment. These enhancements help reduce the

risk of a double drive failure through the use of

proactive hot spares, which allow copy opera-

tions to a hot spare from a failing drive to help

eliminate the rebuild window and reduce expo-

sure to a second drive failure. High availability

is one of the primary advantages of virtualiza-

tion, and Dell/EMC CX3 UltraScale series arrays

can help ensure this availability for enterprises

running VMware software.

Integrating VMware virtualization with flexible, resilient Dell/EMC storage Choosing appropriate storage and storage soft-

ware for a VMware software–based environ-

ment can be critical to maximizing the

advantages of virtualization. By deploying

VMware software in conjunction with Dell/EMC

CX3 UltraScale series arrays, taking advantage

of metaLUN and Virtual LUN technology, and

using EMC Navisphere and Navisphere Quality

of Service Manager software, enterprises can

create flexible, resilient, easy-to-manage virtu-

alized infrastructures.

Andrew Gilman is a product marketing manager

at EMC Corporation overseeing the Navisphere

Management suite and VMware marketing activ-

ities for CLARiiON. Since joining EMC in 2005,

he has held a variety of marketing roles by way

of the Marketing Leadership Development

Program. Prior to EMC, Andrew held both techni-

cal and marketing roles at several successful

startups in the telecommunications field. Andrew

has a B.S. in Business Administration from

Boston University’s School of Management.

QUICK LINKS

Dell/EMC storage: www.dell.com/emc

EMC and VMware: www.emc.com/vmware

Feature Section: Virtualization in the MainStreaM

DELL POWER SOLUTIONS | August 200760

“By deploying Vmware software in conjunction with Dell/emC CX3 UltraScale series arrays, enterprises can create flexible, resilient, easy-to-manage virtualized infrastructures.”