virtualization

DELL POWER SOLUTIONS | May 200794

For many organizations, the question is not if they

will migrate to Microsoft Windows Vista and the

2007 Microsoft Office release, but when. When will

all their mission-critical applications support Windows

Vista? When will their clients be upgraded to meet system

requirements?

What if the same applications in use today could be

delivered to Windows Vista users—without requiring native

Windows Vista support? What if clients that did not meet the

system requirements for new applications such as 2007

Microsoft Office could still access those applications?

Application virtualization and application streaming,

used together, can remove many obstacles to early adoption

of, and migration to, Windows Vista and 2007 Microsoft

Office. Individually, each technique has strengths and limita-

tions. Combined, they provide well-balanced options to accel-

erate migration and help lower total cost of ownership.

Windows Vista includes significant changes that can

affect application compatibility. This 64-bit OS does not sup-

port 16- and 32-bit drivers. New system application program-

ming interfaces (APIs), User Account Control, Windows

Resource Protection, and reduced rights for the Microsoft

Internet Explorer® Web browser can cause compatibility

issues. The 2007 Microsoft Office release, meanwhile, intro-

duces new file formats, making it highly desirable for all users

to run the same Microsoft Office version so that they can col-

laborate and share information effectively.

Separating applications from operating systems In virtualized environments, desktop applications run on a

server, and the user interface is virtually delivered to the end

user over the network. These applications are not dependent

on the local OS or device drivers, have minimal hardware

requirements, and help reduce maintenance.

Although solutions such as Citrix Presentation Server 4.5

software offer advantages in control, security, and cost-

effectiveness (see the sidebar on the next page), some trade-

offs exist with application virtualization. Clients must be logged

on to the network, limiting notebook users. Very long-distance

connections may exhibit lag time. In the past, graphics-intensive

3D applications were challenging to deliver over networks.

Application streaming can deliver applications to clients

for use anytime, even when they are not connected to a net-

work. Applications are cached locally in an isolation environ-

ment rather than installed on the device. This approach helps

eliminate application conflicts and reduce the need for exten-

sive regression testing to certify applications. As a result,

applications can be offered as an on-demand service,

updated quickly, or de-provisioned just as quickly.

Application streaming helps make users independent with

many of the manageability and cost-efficiency benefits of cen-

tralized applications, but there are some trade-offs. Potentially

heavy bandwidth usage can occur when large applications are

first streamed. Applications that require a real-time connection

to a back-end database or are tightly coupled to the OS are not

Related Categories:

Citrix Systems

Microsoft Windows Vista

Virtualization

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How to Jump-Start the Migration to Microsoft Windows Vista

IT groups can accelerate migration to the Microsoft® Windows Vista™ OS and 2007 Microsoft Office by using Citrix Presentation Server™ 4.5 software. Virtualizing applications allows delivery of legacy and new applications to existing clients and those running Windows Vista, while streaming applications enables local and offline operation to help eliminate compatibility issues.

By Chris harget

reprinted from Dell Power Solutions, May 2007. Copyright © 2007 Dell inc. all rights reserved.

95www.dell.com/powersolutions

good candidates for streaming. Combining

application virtualization and application

streaming can give IT groups the flexibility to

dynamically define how to deliver applications

under various scenarios.

Planning strategies for fast rolloutOrganizations typically migrate to a new OS

either all at once or in stages coinciding with

hardware refresh cycles. Migrating all at once

can require a substantial up-front investment

of personnel and budget and can increase

strain on IT staff as users abruptly change to

new applications, but the overall transition is

shorter than a gradual migration.

For a simultaneous migration, virtualiza-

tion can serve applications that do not yet sup-

port Windows Vista, allowing an early migration

date. Old and new applications can be offered

concurrently to help smooth user transition.

For applications that should run locally, appli-

cation streaming can facilitate reliable auto-

matic updates for patches.

Organizations that migrate in planned

phases face different opportunities and chal-

lenges. For example, gradual migration can

maximize the value of older client systems

before retirement, and can help reduce budget

spikes. However, it can also create delays when

a large fraction of users have migrated to

Windows Vista. A common challenge is support-

ing multiple versions of the same applications

across multiple operating systems.

For gradual migrations, application virtual-

ization can serve new applications to old cli-

ents and old applications to new clients. This

flexibility allows end users to migrate applica-

tions at their own pace, independently of the

OS on the client. Virtualization helps maximize

business continuity. Streaming helps simplify

deployment and updating of locally run appli-

cations, as well as helping prevent application

conflicts on old and new operating systems.

Many organizations are expected to transi-

tion users to the 2007 Microsoft Office release

all at once because of the new file formats.

Virtualization and streaming allow client sys-

tems that do not meet the minimum system

requirements or that run a previous-generation

OS to use 2007 Microsoft Office, helping orga-

nizations migrate sooner and at a lower cost

than they could without virtualization and

streaming.

Smoothing the way to Windows Vista IT organizations should develop a comprehen-

sive strategy for migrating to Microsoft Windows

Vista and the 2007 Microsoft Office release that

takes into account application compatibility,

budgets, and other resources available for their

particular environments. Regardless of the spe-

cific strategy, by separating applications from

operating systems, application virtualization

and application streaming can help remove

many obstacles to early adoption of Windows

Vista and 2007 Microsoft Office.

Chris Harget is a product marketing manager

at Citrix.

IT planners exploring how to migrate to new applications such as 2007

Microsoft Office and operating systems such as Microsoft Windows

Vista are looking at application virtualization and application streaming

as strategies to help simplify and accelerate this migration, reduce

administrative burden, and lower costs. Citrix Presentation Server 4.5

combines application virtualization and application streaming into a

single, end-to-end application delivery solution. It provides flexible

policies designed to dynamically choose the best delivery method

based on the user, device, application, and network.

Virtualized applications run in the data center, helping reduce

deployment time and costs. This approach allows legacy clients to

access the latest applications, and Windows Vista clients to access

legacy applications. When users are disconnected from the network

and need a local version of an application, streaming allows applica-

tions to execute locally in a desktop isolation environment without

installation. This approach helps eliminate compatibility issues,

helps reduce regression testing time and cost, and allows centrally

managed applications to run offline. Citrix Password Manager™ soft-

ware provides enterprise single sign-on access to help streamline

secure migration to new application versions.

Figure A shows how Presentation Server 4.5 helps ensure business

continuity during Windows Vista migration by virtualizing and stream-

ing Windows Vista–incompatible applications to Windows Vista cli-

ents, and streaming Windows Vista–compatible applications such as

2007 Microsoft Office to clients running the Microsoft Windows® XP

or Windows 2000 operating systems. For more information, visit

www.citrix.com/presentationserver.

hOW citRix PREsEntatiOn sERvER accElERatEs thE migRatiOn PROcEss

Figure A. Microsoft Windows Vista migration using Citrix Presentation Server 4.5

reprinted from Dell Power Solutions, May 2007. Copyright © 2007 Dell inc. all rights reserved.

Citrix Presentation Server systemsHosting: All applications being streamed or virtualized

Migrated workstationsOS: Microsoft Windows Vista

Running locally:Windows Vista–compatible applications

Running through Presentation Server:Windows Vista–incompatible applications

Non-migrated workstationsOS: Microsoft Windows XP or Windows 2000

Running locally:Windows Vista–incompatible applications

Running through Presentation Server:Windows Vista–compatible applications