Virtualization

Designing a Scalable Architecture for VMware Virtual Desktop Infrastructure By David Korsunsky Timothy Sherbak Cris Banson

To help address the challenges of enterprise desktop management, VMware and Dell have created a scalable VMware® View reference design based on VMware Infrastructure 3, Dell ™ PowerEdge ™ servers, and Dell EqualLogic™ PS Series storage arrays—extending the benefits of virtualization to end-user systems while enhancing administrator control and helping reduce ongoing operational costs.

M

Related Categories: Data consolidation and management

anaging traditional enterprise desktops has

experience to end users. Virtual machine (VM) hard-

become increasingly difficult and costly,

ware independence, encapsulation, and isolation,

presenting challenges such as supporting

combined with features such as VMware vMotion™

rising numbers of remote and mobile users, control-

technology, VMware High Availability (VMware HA),

ling support and maintenance costs, performing time-

VMware Distributed Resource Scheduler (VMware

consuming software management, and meeting

DRS), and VMware Consolidated Backup (VCB), help

stringent requirements for availability, stability, per-

make virtual desktops substantially more agile than

formance, and security. To help overcome these chal-

traditional physical desktop configurations.1

lenges, organizations are constantly looking for

To help organizations implement this technology in

solutions that can provide a simplified, cost-effective

their own environments, VMware and Dell have created

approach to desktop management.

a scalable reference design using a building-block

Given the success of server virtualization in sup-

approach based on VMware Infrastructure 3, Dell

Dell EqualLogic storage

porting consolidation, helping simplify management,

PowerEdge 2950 servers, and Dell EqualLogic

Dell PowerEdge servers

and helping reduce operating costs, organizations are

PS5000XV Internet SCSI (iSCSI) storage area network

Flexible computing

beginning to look for ways to achieve similar benefits

(SAN) arrays. The building-block configuration has been

Internet SCSI (iSCSI)

in desktop environments. VMware View—which

designed, sized, and tested based on VMware and Dell

Storage

includes VMware Virtual Desktop Infrastructure

best practices to support up to 64 virtual desktops,

Storage area network (SAN)

(VDI)—offers an end-to-end solution that enables

each handling a workload representative of a user

Virtualization

organizations to provide end users with access to

running a common set of business applications.

VMware

virtual desktops hosted in a central data center. This

Organizations can use this architecture to help design

Visit DELL.COM/PowerSolutions

solution enables administrators to take advantage of

and fine-tune a deployment that can meet the specific

for the complete category index.

the VMware Infrastructure 3 virtualization platform

needs of their environments. By doing so, they can

along with an enterprise-class desktop manager

create a flexible, scalable environment that extends

and connection broker to enhance manageability

powerful VMware Infrastructure 3 capabilities such as

and control while still delivering a familiar desktop

business continuity and disaster recovery to the

1

46

For more information on the advantages of VMware VDI, see “Extending Benefits of Virtual Remote Desktops Using VMware and Dell EqualLogic SANs,” by Timothy Sherbak and Cris Banson, in Dell Power Solutions, November 2008, DELL.COM/Downloads/Global/Power/ps4q08-20090108-Sherbak.pdf.

DELL POWER SOLUTIONS | March 2009

Reprinted from Dell Power Solutions, March 2009. Copyright © 2009 Dell Inc. All rights reserved.

desktop, streamlines desktop management, and increases administrator control while helping reduce ongoing operational costs.

Applications

Applications

OS

OS

VM 1

VM 32

VMware View reference solution

Virtual desktops

Applications

Applications

OS

OS

VM 33

VM 64

Gigabit Ethernet NICs (VM network)

Each building block of the reference archi-

Dell PowerEdge 2950 server

tecture is designed to support up to 64 virtual desktops per VMware ESX host (8 per core) running a workload profile com-

Gigabit Ethernet NICs (iSCSI network)

monly referred to as a knowledge worker or information worker. This profile, based

Dell EqualLogic PS5000XV iSCSI SAN array

on VMware research on the most common type of desktop worker, is well suited to desktop virtualization. Specifically, the reference architecture was designed and

LUN 1

tested with seven typical enterprise applica-

LUN 2

tions: Microsoft® Word, Microsoft Excel®, Microsoft

PowerPoint®,

Microsoft

Figure 1. Scalable building-block configuration supporting up to 64 virtual desktops

Internet Explorer®, Adobe® Acrobat, WinZip, and McAfee VirusScan software.

applications. VMware HA clusters are

a VMware Virtual Machine File System

Figure 1 shows the building-block

designed to provide continuous service

(VMFS) volume and supporting 32 virtual

design for the target worker profile. The

availability during both planned and

desktops. To take advantage of advanced

overall reference solution comprises four

unplanned system downtime, while VMware

EqualLogic volume virtualization, the data

primary layers, each building on the layer

DRS helps dynamically load balance VMs

volumes are distributed across all active

below to provide a comprehensive plat-

across the entire pool of available resources.

drives and RAID sets in the array.

form for VMware View deployment in

VCB provides centralized, cost-effective

midsize enterprises.

backup to help efficiently protect VMs.

Layer 1: VMware Infrastructure 3

Layer 2: Dell EqualLogic

desktop having its own persistent virtual

VMware Infrastructure 3 provides the foun-

PS5000XV iSCSI SAN array

disk. Although this configuration provides

dation of the reference architecture,

iSCSI arrays are well suited for use with

a good starting point, organizations should

abstracting processor, memory, storage,

VMware View, offering cost-effective, high-

take into account the needs of their specific

and networking resources into virtualized

performance storage for the virtualized

environments before choosing a storage

components that can support multiple VMs

environment.

array, including the following criteria:

while also providing enhanced manage-

PS5000XV array is designed to provide a

ability, increased availability, simplified

high-performance iSCSI SAN based on

disaster recovery, and rapid provisioning

fully redundant, hot-swappable, enterprise-

requirements by collecting disk perfor-

and allocation of desktop and storage

class hardware. Built-in EqualLogic PS

mance statistics on an end-user system

resources. In the reference architecture,

Series software functionality includes

this layer incorporates VMware ESX 3.5

automatic load balancing, snapshots and

Update 2 running on the Dell PowerEdge

replication, multipath I/O, consistency

ments by determining the size of the

2950 server as well as VMware vCenter

sets, and more at no additional cost.

hard drive to be allocated to each vir-

VMware ESX provides the software iSCSI initiator. The storage sizing was based on the use of full clones, with each virtual

The

Dell

EqualLogic

Server (formerly VMware VirtualCenter)

The EqualLogic PS5000XV array used

2.5 software running on a Dell PowerEdge

in the reference architecture is configured

1850 management server.

with EqualLogic PS Series firmware ver-

■■

Performance: Estimate performance

during normal operation. ■■

Capacity: Estimate capacity require-

tual desktop. ■■

Drive type: Choose an appropriate drive type based on performance,

This layer can also include the VMware

sion 3.2.4 and sixteen 146 GB, 15,000 rpm

vMotion, VMware HA, VMware DRS, and

Serial Attached SCSI (SAS) drives in a

VCB features. vMotion enables the live

RAID-50 configuration with two hot-spare

RAID level based on workload charac-

migration of VMs from one physical server

drives. Two 410 GB data volumes are pro-

teristics and how the application

to another without affecting running

visioned on the array, each formatted as

performs I/O.

Reprinted from Dell Power Solutions, March 2009. Copyright © 2009 Dell Inc. All rights reserved.

capacity, and interface requirements. ■■

RAID level: Choose an appropriate

DELL.COM/PowerSolutions

47

Virtualization

■■

iSCSI initiator: Choose an appropriate hardware or software iSCSI initiator.

End users VMware View Portal

The basic reference configuration is

VMware Infrastructure 3 VMware View Administrator

VMware vCenter Server

designed for simple sizing and deployment, but can result in increased costs as it scales up with additional building blocks.

VMware ESX (virtual desktops)

To help reduce storage costs as the solution scales up, organizations can take

VMware View Connection Server

advantage of two additional options: EqualLogic PS Series snapshots and VMware View Composer.2 EqualLogic storage arrays include the

Microsoft Active Directory

VMware View Client

ability to take one or more snapshots of a VMFS volume and provide these snapshots to VMware ESX as new writable data stores. This approach helps reduce storage requirements because virtual desktops

Figure 2. Example VMware View Manager environment

share the desktop images hosted on the originating data volume, thus consuming

into account both cost and I/Os per

additional storage only when new data is

second (IOPS).

■■

Number of ESX servers: Balance cost per VM with the number of ESX servers.

written by an individual virtual desktop.

Very large deployments may favor

Layer 3: Dell PowerEdge 2950 server

servers with increased processor and

ponent of VMware View, uses VMware

Dell PowerEdge servers are designed to

memory resources to support more

linked clone technology to rapidly create

provide a simplified, cost-effective, high-

VMs per ESX server, thereby requiring

desktop images that share virtual disks

performance platform for enterprise data

with a master image. User data and set-

centers, and can easily integrate with

tings are separated from the desktop

VMware Infrastructure 3. The Dell

provides an appropriate balance

image, so they can be administered inde-

PowerEdge 2950 server used in the refer-

between license costs and performance;

pendently. Administrators can patch or

ence architecture is configured with two

two-socket servers with quad-core pro-

update desktops that are linked to a

quad-core Intel® Xeon® processors at

cessors are typically appropriate for

master image simply by updating the

2.67 GHz, 32 GB of RAM, and VMware ESX

master image, without affecting user set-

3.5 Update 2, along with two Gigabit

tings, data, or applications. This feature

Ethernet network interface cards (NICs)

ficient number of PCI slots for network

helps reduce storage needs and costs

for the VM network and two Gigabit

and storage connectivity to provide

while simplifying desktop management.

Ethernet NICs for the iSCSI SAN. This con-

VMware View Composer, a new com-

fewer ESX servers to manage. ■■

ESX license costs: Choose a server that

VMware View environments. ■■

PCI slots: Ensure the server has a suf-

both high availability and resiliency. vMotion compatibility: Ensure that all

Administrators should deploy these

figuration helps provide a good balance

options carefully, because they can poten-

between overall server hardware cost and

ESX hosts in the VMware View environ-

tially affect performance by increasing the

sufficient performance to support the

ment have compatible processors for

load on a limited set of shared storage

64 virtual desktops. As with the storage

vMotion, especially if the hosts will be

resources. A classic storage-sizing trade-

layer, organizations should take into

part of an existing ESX cluster.

off exists between optimizing cost and

account the needs of their specific envi-

capacity and optimizing performance. The

ronments before choosing a server, includ-

Layer 4: VMware View Manager

performance requirements as defined by

ing the following criteria:

and clients

the target workload for the reference

■■

The final layer in the reference solution is Cost per VM: Choose a server that pro-

VMware View Manager and the client

workload for this type of environment is

vides an appropriate balance between

systems. VMware View Manager is an

nontrivial and characterized by bursts of

overall cost and the number of VMs it

enterprise-class desktop management

activity, requiring storage sizing to take

can run in a production environment.

platform designed to securely connect end

solution indicate that the aggregate I/O

2

■■

VMware View Composer requires VMware ESX 3.5 Update 3 and VMware vCenter Server 2.5 Update 3.

48

DELL POWER SOLUTIONS | March 2009

Reprinted from Dell Power Solutions, March 2009. Copyright © 2009 Dell Inc. All rights reserved.

users to virtual desktops in the data center, and includes a simplified Web browser–

35,000

based interface to manage VMware View

30,000

Active Directory® infrastructures for

25,000

Memory (bytes)

environments. It uses existing Microsoft authentication and user management, and integrates with VMware vCenter Server to manage virtual desktops on VMware ESX. VMware View Manager includes the following primary components (see Figure 2):

20,000 15,000 10,000 5,000

8:18:49

7:54:17

7:29:42

7:05:10

6:40:37

6:16:05

5:51:32

5:26:56

tion that communicates with View

5:02:23

0

View Client: Locally installed applica-

4:37:50

■■

Free memory Shared memory

Connection Server to allow users to connect to their desktops using

Figure 4. VMware ESX memory utilization on a Dell PowerEdge 2950 server supporting 64 virtual desktops

Remote Desktop Protocol (RDP) ■■

View Portal: Web browser–based version of View Client supported by mul-

■■

■■

performance monitoring tool. Figure 3 shows the test environment.

architecture is configured with one virtual

View Administrator: Web browser–

processor, 512 MB of RAM, and 10 GB of

Figure 4 shows the VMware ESX

based application that serves as the

disk space, and runs the Microsoft

memory utilization as measured by the

primary mechanism for configuring

Windows® XP Professional OS with Service

esxtop tool when running 64 virtual desk-

View Connection Server and managing

Pack 2, Microsoft Office 2003 suite, and

tops on a single Dell PowerEdge 2950

users and desktops

VMware View Agent software.

server. Actual memory usage and page

View Connection Server: Software

sharing increased and decreased slightly during the four-hour test run as the virtual

provides management and user

Test environment and performance

authentication for virtual desktops

In November 2008, VMware carried out

cations, with utilization averaging approxi-

View Agent: Software that installs on

performance testing on the reference solu-

mately 19 GB. As the test progressed,

virtual desktops and enables features

tion using the VMware View Performance

additional common pages were found in

such as RDP connection monitoring,

test software along with VMware vCenter

memory for all the virtual desktops, enabling

remote USB support, and single sign-on

Server, esxtop, and the Dell EqualLogic

the server to reclaim approximately 13 GB

that acts as a connection broker and

■■

Each virtual desktop in the reference

tiple operating systems and browsers

desktops opened and closed common appli-

of memory over the course of the test and helping demonstrate the efficient memory usage of the test environment. VMware vMotion virtual LAN Production network iSCSI network

Figures 5 and 6 show the storage

Dell PowerEdge 1850

(VMware vCenter Server, VMware View Connection Server, and domain controller)

IOPS and throughput measured by the EqualLogic performance monitoring tool on the EqualLogic PS5000XV array when

Dell PowerEdge 2950

running 64 virtual desktops. Performance

(VMware ESX)

Wide area network

averaged approximately 185 IOPS over the course of the test run, with a peak of

Dell PowerEdge 2950

approximately 650 IOPS; throughput

(VMware ESX)

Dell PowerEdge 2950

Dell EqualLogic PS5000XV iSCSI SAN arrays

(VMware ESX)

averaged approximately 3,530 KB/sec, with a peak at 13,733 KB/sec. One of the advantages of the EqualLogic array is that the VMFS data store volumes are

Gigabit Ethernet switch

Gigabit Ethernet switch

virtualized—that is, striped across all drives in the array—thus distributing the aggregate workload across the available

Figure 3. Test environment based on the VMware View reference architecture Reprinted from Dell Power Solutions, March 2009. Copyright © 2009 Dell Inc. All rights reserved.

storage resources. This approach enables DELL.COM/PowerSolutions

49

Virtualization

their own ESX cluster or be part of an existing ESX cluster containing other

700

server workloads.

Performance (IOPS)

600 ■■

500

VMware vCenter Server instances: Consider whether the virtual desktops

400

will be managed by their own dedicated

300

vCenter Server instance or by an exist-

200

ing vCenter Server instance that may already be managing other non–VMware

100

View deployments. 5:02:00

4:52:00

4:42:00

4:32:00

4:22:00

4:12:00

4:02:00

3:52:00

3:42:00

3:32:00

3:22:00

3:10:00

3:00:00

2:50:00

2:40:00

2:30:00

2:20:00

2:10:00

2:00:00

1:50:00

1:40:00

0

Comprehensive solution for desktop virtualization Organizations today must support a wide

Figure 5. Storage performance on a Dell EqualLogic PS5000XV array supporting 64 virtual desktops

variety of users on a range of equipment— including local, mobile, and remote users

Throughput (KB/sec)

accessing sensitive information assets 16,000

across desktops, laptops, and unmanaged

14,000

PCs—making it difficult to support end users in a consistent and secure manner.

12,000

By combining the advantages of VMware

10,000

Infrastructure 3 and cost-effective, high-

8,000

performance Dell servers and storage, the

6,000

reference solution described in this article provides a robust basis for virtual desktop

4,000

environments, one that can help both con-

2,000

trol ongoing costs and easily scale as busi5:06:00

4:54:00

4:42:00

4:30:00

4:18:00

4:06:00

3:54:00

3:42:00

3:30:00

3:18:00

3:04:00

2:52:00

2:40:00

2:28:00

2:16:00

2:04:00

ness needs grow. 1:52:00

1:40:00

0

David Korsunsky is a storage solutions engineer on the VMware Storage Alliances team.

Figure 6. Storage throughput on a Dell EqualLogic PS5000XV array supporting 64 virtual desktops Timothy Sherbak is senior manager of virorganizations to add performance capac-

pilot end users. This approach provides an

tualization solutions marketing for the Dell

ity simply by expanding the SAN with an

opportunity to establish baseline perfor-

EqualLogic product family.

additional storage array, which can be

mance measurements on the system to

seamlessly added to the EqualLogic

help ensure that the sizing estimates are in

Cris Banson is a senior technical storage

group. The EqualLogic storage can then

line with actual production use.

specialist at VMware.

automatically redistribute the data

As organizations scale the environ-

volume and disk I/O across the additional

ment and deploy additional building

controller, network ports, memory cache,

blocks, they should keep the following

and disk spindles.

design considerations in mind:

Deployment and scaling

■■

VMware configuration maximums:

Designing and testing a server and storage

Always check the latest VMware con-

building block for a typical worker profile

figuration maximums before scaling up

enables organizations to use the VMware

a deployment, particularly in large environments.

View reference configuration as a basis for their own deployments. Ideally, administra-

■■

VMware ESX cluster design: Determine

tors should deploy the first building block

whether the ESX hosts running the

as a proof-of-concept test with a group of

virtual desktop environment will form

50

DELL POWER SOLUTIONS | March 2009

QUICK LINK VMware View: www.vmware.com/products/view

Reprinted from Dell Power Solutions, March 2009. Copyright © 2009 Dell Inc. All rights reserved.