Desktop virtualization: Making PCs manageable

joey

September 12, 2006
(InfoWorld)
-- Managing PCs has always been painful, but the
job has gotten considerably nastier, thanks to an endless parade of application
upgrades, operating system patches and antithreat updates. Even with
network-based installation and patch management tools to ease the burden, IT
spends far too much time at the desktop itself, dealing with shenanigans
involving personal software; multiple versions of Java or ActiveX controls;
driver or Dynamic Link Library (DLL) conflicts; malware infections;
misconfigured hardware; and more.
The promise of desktop virtualization technology is to centralize
applications at the data center to make them easier to manage and provision --
stretching hardware resources and keeping nagging software conflicts to a
minimum in the bargain. In some cases, the same technology helps accomplish all
three, bringing greater control and flexibility to IT without users mourning the
loss of "their" beloved desktops.
At first blush, desktop virtualization sounds a lot like terminal services,
such as those provided by Citrix Systems Inc., where servers run the
applications and give users remote access. All the user's terminal or PC does is
present the updated screen display and permit input via keyboard and mouse.
Desktop virtualization, on the other hand, is a new way of delivering the
individual PC environment that white-collar workers demand and love. In essence,
servers host an entire desktop environment specific to each user.
The early versions of desktop virtualization were blade servers, such as
those offered by ClearCube Technology Inc. and IBM, that simply moved the
processing guts of a PC to the data center and left the input and display at the
user's desk. But the latest versions use the PC at the user's desk for much of
the processing. Dubbed "desktop streaming," this approach retains the benefits
of central management without throwing away the desktop's power. The needed code
is streamed to disk and memory cache for just that session, ensuring that
there's nothing for the user to mess up or alter.
A few providers go beyond desktop streaming to application streaming, where
IT can send out the runtime cache for individual apps as needed. This reduces
the number of unique user images to maintain and provides better insight into
which application licenses are really needed.
Building a better thin client
The greatest benefit of desktop virtualization is the ability to provision
PCs and other client devices with software from a central location. IT can
manage a large number of enterprise clients from the data center, rather than at
each user's desk, reducing on-site support and increasing control of application
and patch management.
At its simplest, virtualization on the application server side reduces
hardware costs by letting one server provision multiple desktop clients, rather
than having one server per desktop client, says John Humphreys, an IDC analyst.
And virtualization also adds the ability to move desktop environments and hosted
applications as needed for load-balancing or fail-over. To make existing
terminal services and blade systems work with virtual machines, established
providers, such as Citrix and ClearCube, have developed broker technology to let
IT manage the mapping to virtual resources.
Citrix, ClearCube and Wyse Technology Inc. now support the use of VMware and
Microsoft virtual machines on blades and other application servers. VMware also
offers Virtual Desktop Infrastructure (VDI) software, which makes server-hosted
virtual machines accessible to users through the Remote Desktop Protocol
(RDP).
Bell Canada uses VDI to provision desktops to call center users, letting them
work in other locations or even at home without burdening IT support, notes
Martin Quigley, senior solutions adviser for adaptive infrastructure at Bell
Systems & Technology, which manages Bell Canada's call centers. "RDP is
quite thin," he notes, so it does not burden the network. But Quigley looks
forward to the next release of VMware's underlying ESX technology, which will
support load balancing across servers, making it easier to maintain performance
levels as user demands change. (Currently, this is a manual process.)
At Duncan Regional Hospital in Duncan, Okla., the number of desktops more
than doubled to about 500 in the past two years. Rather than lobby for money to
hire more desktop support techs, CIO Roger Neal decided to deploy ClearCube thin
clients and keep the physical management in a central location -- and get more
from his existing staff. When ClearCube began supporting VMware virtual machines
in 2006, Neal began reconfiguring his blade servers to run three virtual
machines per blade, so he wouldn't need more blades as the demand for desktops
increased. He also saw desktop support calls drop by 40%, which he attributes to
centralized PC management.
Streaming to the desktop
Virtualization at the application host server can make thin clients more
efficient to deploy, but many organizations are wedded to having real PCs at
users' disposal despite the support costs. Desktop streaming is emerging as one
of the most efficient ways to support this model without incurring the usual
bloated desktop support costs.
A growing number of vendors, including Ardence Inc., Propero Ltd., Stream
Theory Inc. and Wyse, offer desktop streaming software that provisions the
entire desktop environment from a server to a desktop PC (or thin client).
Altiris Inc., AppStream Inc., and Microsoft Corp. (through its recent
acquisition of Softricity Inc.) have pushed the concept to the next level,
streaming applications rather than a complete desktop environment. This allows
greater flexibility in what is provisioned, because IT can create a basic
operating system image and then individual images for each application, and
combine them as needed on the fly. You don't need a separate desktop image for
each combination of applications.
With both desktop and application streaming, the provisioned operating system
and applications use the client's local resources, without the overhead of
permanent installation on the client. For example, financial services firm
Russell Investments Group saw application deployment shrink from four weeks to
one and a half weeks after it began using Microsoft's SoftGrid, says Greg
Nelson, an IT analyst at the company.
Typically, a set of stub services is transferred to the local cache at
connection time, and other resources are streamed as needed. "When you run an
application, you need only 15% to 20% to start using it, so it can be network
delivered," says David Grescher, director of marketing for SoftGrid.
Streaming does delay initial application access, says Bill Washburn,
operations analyst at California State University at San Marcos, which uses
technology from Altiris. "But once the application is installed, people say it's
the best they've ever seen it run," he says.
Nelson says that although desktop and application streaming should
theoretically use more network resources than terminal services do, that's not
always the case. For example, printing and working with large files can swamp
the network in a traditional terminal services architecture. Desktop and
application streaming can avoid that by using local printers and local
storage.
Simplifying management
One big advantage of streaming is that IT has fewer images to maintain. That
benefit applies in spades to application streaming products from Altiris and
Microsoft.
For example, CSU's Washburn says that Altiris' Software Virtualization
Solution solves a long-standing annoyance with SPSS Inc.'s statistical software.
Each year, a new license key is issued and must be updated at every user's
desktop. But with Altiris' software, Washburn simply updates the server copy,
which is provisioned to users automatically when they call the application.
Although the technologies from Ardence, Propero, Stream Theory and Wyse
centralize applications and data, they also let users store data locally as well
(a PC's C drive is remapped to become its D drive when their software runs).
Moreover, because Altiris' and Microsoft's application streaming tools let users
set up applications in their own virtual layer or session, IT can avoid the
regression testing across the whole application set whenever a program is
modified or added, says Nelson.
With the applications from Altiris, AppStream and Microsoft, the client PC
can have its own operating system and applications installed, while the server
pushes centrally provisioned applications into local desktop caches. In this
fashion, IT can distribute resources selectively. For example, Russell's Nelson
installs Windows with applications that act as extensions to the operating
system (such as Adobe Acrobat Reader, Apple Quicktime and Java) on local PCs --
plus Microsoft Office and a few other frequently used applications on local PCs.
Then he uses SoftGrid to provision other applications as streams.
This selective approach can also help balance performance, notes CSU's
Washburn. Were Washburn to deliver everything as streams, it would take client
PCs five minutes or more to boot up -- a nonstarter. So he installs core
applications on the PCs the old-fashioned way, using Altiris' remote deployment
tools and provisions less frequently used programs via application
streaming.
Yet another variation is to combine application streaming with terminal
services. At Alamance Regional Medical Center in Burlington, N.C., senior
network administrator Andy Gerringer uses both Citrix and SoftGrid to provision
desktops. Citrix is used in the usual manner to deliver server-based
applications as individual sessions. But Alamance also uses Citrix to provide
access to a SoftGrid desktop environment for terminal users. Essentially, the
Citrix session runs the SoftGrid virtual machine. "SoftGrid and Citrix
complement each other very well," Gerringer says.
Conflict resolution for applications
Application streaming comes with a significant side benefit: eliminating
application conflicts. The application streaming tools from AppStream, Altiris
and Microsoft separate application-specific support files, such as DLLs and
libraries, from the underlying operating system. Altiris separates just the
support files, keeping the applications with the operating system, whereas
AppStream and Microsoft keep each app and its support files together in one
virtual layer or package.
These programs manage the communication among the layers and the underlying
operating environment, so both Windows and its users think they are working on a
single environment.
By separating each application into its own virtual layer (or package, as
some call it), these products prevent software conflicts common with homegrown
software and some commercial applications. And user-installed applications can't
conflict with IT-provisioned applications in the virtual layers, says SoftGrid's
Grescher.
For example, before adopting SoftGrid, recalls Alamance's Gerringer, the
medical center had to maintain separate servers for ill-behaved apps, forcing
users to switch among multiple systems from their terminals. "By summer 2005,
the problem got too big to manage anymore the old way," Gerringer says.
The problem? Different versions of Java used by various specialty health care
apps prevented simultaneous usage, as did the embedding of different versions of
the Crystal Reports reporting tool in other applications. (If Crystal Reports 4
is running, Crystal 5 cannot run, for example.)
Now that Alamance uses SoftGrid, users get a unified desktop environment,
with the ill-behaved apps corralled so they can no longer cause trouble.
The new reality of virtualization
Desktop and application streaming require IT to think differently about tasks
that they've done for years, notes Duncan Regional Hospital's Neal. "It takes a
little more thought in the rollout," he says. For example, his support staff now
has to keep an eye on the blades that serve the desktop environments, because a
broken fan can cause them to overheat, knocking out multiple users in one blow.
His staff also must monitor disk usage for each blade, because 80GB is shared
among three users.
Virtualized desktops can be provisioned to specific client hardware, so a
particular call center terminal always uses the same virtual machine on a
specific blade. But they can also be provisioned to specific users, based on
user log-in, so the client device running them could be anywhere. That can pose
a challenge for setting up access to printers and departmental file servers,
depending on how mobile users are, observes Bell Canada's Quigley.
Quigley notes another issue that can puzzle support staff: Users connecting
from home may not get their DNS address resolved properly, so IT tends to assign
a fixed IP address to get around that issue. But the Windows virtual machines
are rebooted each night to deal with memory leaks, and the IP address for that
virtual machine might no longer match what is set up in the remote user's home
system.
Nonetheless, early adopters all agree that these relatively minor issues are
far outweighed by the benefits of central administration of fewer desktop
images. As IDC's Humphreys says, "There are some really pragmatic reasons that
this is taking off."
               
               
               

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