Hosting virtual desktops: Tips for a successful outcome

How do you calculate and quantify those advantages, choose the right technology and build out a successful hosted virtual desktop infrastructure (VDI)?

If you've already virtualized the servers in your data center, desktop virtualization may seem like the next logical step. But businesses are finding that the benefits of hosted virtual desktop technologies are more nuanced. The advantages may be harder to quantify and harder to justify based purely on traditional ROI calculations.

So, how do you calculate and quantify those advantages, choose the right technology and build out a successful hosted virtual desktop infrastructure (VDI)? Computerworld asked consultants, analysts and users who have been there to report on what works, what doesn't and how you can learn from their experiences. The first place to start, they say, is with a clear-eyed understanding of the potential benefits.

Desktop virtualization

The gains you should expect from hosted desktop virtualization projects are very different from what accrues from server virtualization. While server virtualization produces visible savings by consolidating physical server hardware and increasing resource utilization, most shops will find that hosting virtual Windows PCs requires a greenfield build-out of new infrastructure in the data center.

But that hasn't stopped some IT shops from exploring the options.

When it comes to hosted virtual desktops, many organizations are already kicking the tires. "Most of my customers are asking about it, if not going to a proof of concept," says Scott Mayers, a principal director at Align, an IT solutions provider focused on the financial services and retail industries.

"2011 is the year when a lot of those concepts will mature into actual deployments," says Ian Song, an analyst at IDC. But so far, he adds, most deployments are still fairly small-scale. The market research firm projects that only about 13.5 million out of 400 million PC shipments this year will be VDI implementations -- just over 3%. By 2014 that number will more than double, to 34 million, accounting for nearly 7% of the market.

Song expects the trend to eventually top out at about 15% to 18% of all enterprise desktops. Gartner's figures are even more conservative. "While it's a big opportunity, we believe that only 10% to 12% of the installed base of PC users will actually use it over the next two to three years," says Mark Margevicius, an analyst at Gartner. It's a technology that needs to be chosen for the right use cases, he explains.

While VDI is at the top of the hype cycle today, there are many flavors and options. For example, you can choose a "persistent" desktop, where every user gets his own dedicated, fully customizable installation of Windows residing within a hosted virtual machine, or go with the more efficient "nonpersistent" VDI model, in which many users' virtual desktops are spun up from a single, common cookie-cutter disk image.

VDI shipments

Percentage relates to the total of all PC desktop shipments.

2011 -- 13.5 million seats -- 3%

2014 -- 34 million seats -- 7%

Source: IDC

There is no one-size-fits-all solution. "Every group has its own set of requirements and parameters," so a different mix of technologies may be appropriate for different groups within an organization, says Steve Kaplan, vice president of the data center virtualization practice at infrastructure services provider INX. And for some applications, the technology simply doesn't make sense.

The cost of deployment has been coming down also, although the upfront investment in data center infrastructure is still high. "We don't envision hosted desktops being less expensive than a PC, from a capital investment standpoint," Margevicius says. He puts the total cost at about 1.3 to 1.5 times what IT would pay for a traditional PC deployment. "The initial capital investment is the limiting factor for our clients," he says.

On the plus side, desktop virtualization's benefits include better security, operational efficiencies and faster restoration in the event of a business outage.

Given all that, how do you navigate through the process? Consultants and users recommend a cautious, methodical approach. Here are some considerations as you move from a review of the basic value propositions and potential use cases into pilots and actual deployments.

Understand the basic value propositions

Client virtualization strategies are often built around three drivers, says Gartner analyst Chris Wolf:

1. Security. Client virtualization lets companies meet compliance or regulatory requirements, since no applications or data reside on the local machine; everything is managed on the server side.

2. Business continuity. If a client device fails, the user can log in elsewhere and pick up where she left off.

3. Operational efficiencies. These include easier management of centralized resources, and the ability to provision new virtual desktops and deploy applications and updates faster. "If there's an issue, it's easy to whip up another virtual session instead of swapping out physical hardware," says Align's Mayers.

Mick Slattery, global lead of workplace enablement services for Accenture and Avanade, says that without another infrastructure move, it may be hard to justify the capital outlay required for VDI all by itself.

The Co-operative Group, the United Kingdom's largest retailer with food, pharmacy, travel and other interests, has so far moved 900 of its 19,000 employees onto Windows XP virtual desktops, and it plans to step those up to Windows 7. "It's the slickness of doing it I like," says technical architect Ian Cawson, comparing the XenDesktop VDI to his traditional software distribution tool, Altiris, for distributing massive updates across all 2,500 of Co-operative's locations. "Altiris would kill the network" in terms of bandwidth, he explains. "And we don't have to reimage." .]

The consumerization of the client is exactly what St. Luke's Health System is addressing. The Summit, Mo., healthcare provider has a pilot under way that delivers a virtualized Windows 7 desktop to doctors on personal iPads that they bring to work. In this way, they can access clinical applications that provide patient information as they move from room to room.

In fact, IT can no longer ignore the increasing clamor of requests to provide access to corporate resources from smartphones, tablets and other consumer-owned devices. As the pressure to accommodate such devices continues to mount, Slattery sees client virtualization as an "interesting first step."

"It allows IT to maintain a level of control and security and still meet the users' needs," although, he says, "you do have some presentation issues" when deploying a virtual desktop or desktop application to a tablet or smartphone screen.

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Desktop virtualization may be a good way to eliminate the need for laptop computers that travel between home and office, if users already have a PC or thin client in each location, says INX's Kaplan. "Virtualization follows them around," he says.

The retail chain Rent-A-Center, for example, recently launched a desktop virtualization pilot. KC Condit, senior director of information security and support, hopes to avoid having to give laptops to the 425 store managers who travel to as many as eight stores each week. Instead, he hopes to equip those managers with a hosted virtual desktop that's accessible from a home computer or from a thin client in any store. .]

St. Luke's Health System empowers doctors with iPads

St. Luke's Health System is turning doctor-owned iPads into virtual Windows desktops. The healthcare provider is using Citrix XenDesktop software provide secure access to clinical applications from the tablets. The proof-of-concept project could end up supporting hundreds of iPad-toting physicians, as well as Android devices and Windows laptops, says Michael Kamer, manager of technology integration services. "We're going to more of a bring-your-own-computer scenario," he says.

Kamer is also testing XenDesktop with thin clients at nursing stations. The hospital keeps the virtual desktops running after the nurses log out to avoid long log-in and application load times. The reason: Nurses must log in and out often, for patient privacy reasons. "They may log in to an application 30 or 40 times per day. If we keep them running [after they log out], they can continue to use the same session," he says.

St. Luke's started with XenApp, which runs applications on top of a Microsoft Remote Desktop Services terminal session and delivers the applications via a Web interface. But getting through a smart-badge log-in process and then loading the application required 40 to 50 seconds. With XenDesktop, he says, "we're now down to 5 seconds."

One big caveat: Remote access using XenDesktop requires a special security setup. Because the hospital doesn't consider user-owned devices to be secure, each must connect to a guest network and use a two-factor authentication process that requires users to present guest tokens. "We're not going to get a lot of user satisfaction with that," says Kamer, so the project is unlikely to go live until Citrix and Apple work out a way for the hospital to use certificates instead.

-- Robert L. Mitchell

Rent-A-Center's virtualization pilot, based on XenDesktop, could become a secure access method for hundreds of contractors, temps and business partners -- and it may set the stage for the company's ultimate goal: getting out of the business of issuing and supporting client hardware. "This paves the way for a bring-your-own-computer model, which is what I want for contractors this year and employees next," says Jai Chanani, who as senior director of technology services and architecture at Rent-A-Center also worked on the networking and data center infrastructure designs for the project.

Chanani isn't the only one with that vision. "We're enabling the business to let people use their own devices," as long as Citrix has a Receiver client for it, says Cawson at The Co-operative Group. "We will allow BYOC this year for iPads," he says, just as soon as Citrix releases Version 13 of its Receiver client. Support for other devices will follow.

Going green

Some organizations are looking for green benefits. For example, Align has a large financial services customer that uses high-performance PCs for real-time trading. The client is considering replacing a second, general-purpose PC on each desk with a virtual desktop and thin client to save both space and power. "It's not just the power on the trading floor, but also the heat associated with those PCs," Mayers says.

The Co-operative Group chose thin clients instead of full-fledged PCs for 90% of the desktops in its new head offices, which come online in 2012. It expects to reduce annual desktop maintenance costs by about $2.4 million and energy costs by about $800,000.

Some retail customers are replacing aging Windows XP-based point-of-sale registers with virtual desktops and thin clients. "We hook up a credit card machine and scanner and have them controlled by corporate without putting any PCs in store locations," Align's Mayers says.

Just make sure the equipment you have is supported by the virtualization vendor. Steven Porter, CIO at Touchstone Behavioral Health, uncovered just this issue during a recent pilot with VMware View. [See sidebar.] Staff in the field had USB-powered signature pads attached to their laptops -- and the VMware client mistook this device for a mouse. Although the manufacturer of the signature pad has a workaround, Porter says it's clunky.

"I don't think I could get my end users to use it," he says. "That was a deal-breaker."

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Once you've figured out the appropriate use cases, INX's Kaplan recommends creating a project definition document that clearly states the business reasons behind the project, as well as the benefits and expected ROI. "When you hit the inevitable hurdles -- like when the assistant to the vice president breaks down because he can't print and wants to get rid of this VDI stuff -- you'll have this touchstone you can go back to."

Hosting virtual desktops is about separating the physical personal computing device from the Windows operating system and applications, which normally run on top of it, and moving it into the data center, where it can be more easily managed. Vendors offer several variations on this theme.

Understand the technology options

The most popular technology today for desktop virtualization is VDI. This is exemplified by VMware View, in which instances of Windows XP or Windows 7 run within virtual machines that are separated from the underlying physical server host. This separation happens by way of a layer of software, such as the VMware vSphere Hypervisor. That software lets each virtual PC think it has exclusive access to the hardware while serving as the traffic cop for all requests to the shared hardware underneath it.

Rent-A-Center: Virtual desktops trump laptops

KC Condit, senior director of information security and support services at Rent-a-Center, faced a challenge. Some managers of the rent-to-own retail store chain needed access to corporate applications, both from the six to eight stores they visit each week and from home.

In addition, the 13,000 aging Windows XP thin clients in the stores are slow -- and users don't always like the look and feel of the thin clients. Managers can use these clients to connect to their applications by way of the Web-based user interface delivered by Citrix's XenApp.

The thin clients, which need a local browser to function, had already been updated to run Internet Explorer 7. But the limited compact flash memory in each machine couldn't keep up with temp file, swap space and other storage needs, while Web-centric programs like Flash bogged down the processors, Condit says.

Rather than issuing laptops to all 425 managers, Condit launched a XenDesktop pilot to improve performance from the stores' aging thin clients, since no local browser is needed, and to allow managers to securely access their virtual desktops and hosted data from any personal computing device, either at home or at work.

Jai Chanani, senior director of technical services and architecture, worked on the networking and data center infrastructure for the pilot. The project is, he says, a cost-avoidance play. The goal is to extend the life of the thin clients by presenting applications in a hosted Windows 7 environment, and avoid the need to invest in laptops and related endpoint security to protect corporate data.

There were some infrastructure issues to address. Rent-A-Center ended up switching to a different SAN and a new caching algorithm for its desktop virtualization back end. Bandwidth needs have also factored in. "It's not just the amount of bandwidth that desktop virtualization uses but when you are using it," Chanani says. The analysis is still in the early stages, but so far Rent-A-Center has needed to upgrade network links at 10% of its locations.

What users are allowed to do also needs to be controlled. For example, users can print at work but not from home, no data resides locally, and data cannot be copied to the user's local device or to a USB disk.

The project is on track to begin production deployments in the second quarter of this year.

-- Robert L. Mitchell

Of course, you can define desktop virtualization more broadly -- as a way to remove the Windows desktop environment from the physical PC and host it in the data center. This idea has actually been around since Microsoft introduced Terminal Services (now Remote Desktop Services) with Windows NT 4.0 back in 1996.

This software served up hosted Windows applications within terminal sessions, with Windows Server functioning as the underlying multiuser operating system. Citrix has extended that approach to include the presentation of a simulated Windows desktop operating system environment using RDS/Windows Server.

In both cases, the connection methodology is similar: A physical client (either a thin client or personal computer running special client software) exchanges keystroke, mouse and display information with a simulated Windows desktop running in a terminal session, or a Windows virtual machine residing on a back-end host.

The technology has improved since those early days of server-based computing. Today the performance is faster than ever, the user's virtual desktop can include whatever level of personalization that company policies allow, and in the RDS model, users can work within a complete virtual desktop environment rather than pick from a slim menu of virtualized applications.

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Hosted desktop virtualization

You virtualize the entire Windows desktop environment, including applications, and host them in the data center. The user then interacts remotely with the hosted virtual desktop by exchanging keystroke, mouse and video screen updates with it.

Vendors offer two approaches based on the VDI model. Under the first option, the persistent VDI design gives every user his own virtual desktop that runs within a virtual machine on a back-end server. Each user gets his own virtual desktop that spins up from a unique, dedicated virtual machine image file containing a full install of Windows. The user owns the image, and any changes that he makes to it will be saved.

The second option presents a "nonpersistent" virtual desktop, which gets spun up on demand from a common "golden" image file and serves multiple users. When a user logs out, any changes made to the virtual desktop disappear.

Citrix presents a third option: Its "hosted shared virtual desktop" follows its XenApp/Presentation Server (server-based computing) model by offering up a simulated Windows desktop in an RDP session on Windows Server.

In cases where organizations were already using XenApp for application delivery, some IT departments have decided it would be more cost-effective to roll out XenApp as a platform for hosted shared virtual desktops rather than build a new infrastructure for VDI, says INX's Kaplan. Technically, however, he doesn't consider it to be a virtual desktop technology, since users are really running a shared Windows Server operating system, not a native Windows XP or 7 desktop operating system hosted within a virtual machine.

"While it is possible to do almost anything with XenApp that one can do with VDI, it can become very complex and burdensome. That is why it never took off as a mainstream desktop replacement solution despite the overwhelmingly compelling economics," Kaplan says. "At the root of the problem, you have Windows Server being used in a way it was never designed for."

Most of the Citrix virtual desktop deployments he's seen to date have used Citrix's XenDesktop to host nonpersistent VDI desktops, he says.

User virtualization: The next tech level

User virtualization brings desktop virtualization to the next level: separating users and the unique attributes of their work environment from both the client hardware and the virtual desktop image. The idea is to allow access from any Internet-connected device, be it a laptop, a tablet PC or a smartphone, and regardless of whether it's running a native Windows, Mac or Android operating system. That ability to achieve seamless portability across many different device types is available now but still evolving.

It is possible (although not always practical on smaller screens) to deliver a full Windows desktop -- or individual applications -- to a smartphone or tablet. Citrix offers versions of its Receiver client software for accessing virtual Windows desktops from both the Android and iOS mobile operating systems, as well as from PCs running the Windows, OS X and Linux desktop operating systems. The VMware View Client is available for the Mac, Windows and the iPad. (A Linux version of VMware View Client is available to OEMs such as thin-terminal manufacturers.)

While the client software generally supports devices running all of those operating systems, not every personal or mobile computing device will work flawlessly, nor will all the peripherals you attach to a thin client or personal computing device running desktop virtualization client software. It's important to check each virtualization software vendor's hardware compatibility list.

And in a cross-platform environment, not everything works together. For example, Citrix Receiver will stream applications only to Windows-compatible client hardware.

A lack of offline access has long been an Achilles' heel for virtual desktop technologies. Both Citrix and VMware recently introduced support for offline mode (VMware calls it "local mode"), which moves the virtual desktop image to the user's laptop and keeps it synchronized with the host version, through manual or automated updates, whenever the user has a connection.

But the technology is still maturing. "Our customers have not really adopted [offline features] yet, but we are looking at some pilots," says Scott Mayers, a principal director at Align.

-- Robert L. Mitchell

Going with the approach of nonpersistent virtual desktops saves on back-end management and infrastructure costs, since the approach uses a few golden image files rather than one for each user, and that takes up less networked storage space.

When users log out, their virtual desktops can be shut down. But it's more typical to keep the virtual desktops in a suspended state so that users can get up and running more quickly when they log back in. In fact, for nonpersistent virtual desktops, administrators may keep a pool of virtual machine sessions running or in a suspended state all of the time so that new users can get up and running quickly after logging in.

Before rolling out VDI, slow boot-up times on older PCs were one of the biggest user complaints, says Kevin Summers, CIO at Whirlpool. Now, early users of VDI are finding that they're up and running more quickly. "Employees aren't as frustrated," he says. .]

Application virtualization

You can virtualize individual applications -- using products such as VMware's ThinApp, Microsoft's App-V or Citrix XenApp -- and then deliver those into a virtual desktop or stream them down to a physical PC on demand and have them run locally. "Application virtualization is really software distribution done in a different way," Accenture's Slattery says.

The technique also promotes stability and eliminates application conflicts by isolating the application from other Windows apps as well as from the Windows operating system. No changes are made to the registry or other settings, so this mechanism can be used to, for example, run two versions of the same application side by side, or to avoid compatibility issues when running an old Windows XP application on top of the Windows 7 operating system.

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User state virtualization

Finally, there's personalization: Virtualization of each user's personal settings, such as wallpaper and other configuration preferences, by storing that data in roaming user profiles or by using third-party tools from vendors such as AppSense or RES Software.

Some third-party tools can store more granular operating system and application settings and even one-off programs. Then the basics are loaded into a plain vanilla nonpersistent VDI session or a hosted shared virtual desktop session at runtime. The rest of the settings and information, such as Word macros, are streamed on demand as needed so users can get up and running more quickly.

"Roaming profiles give users the flexibility to roam between [devices] and preserve the user experience," says Gartner's Wolf.

Personalization tools offer the best of both worlds. They allow users of nonpersistent virtual desktops to maintain a customized work environment while administrators enjoy the efficiencies that come from maintaining a small group of shared virtual desktop image files. For this reason, says Gartner's Margevicius, "this will be the key technology for most customers over time."

"Customers ignore personalization at their peril," says INX's Kaplan. Not all users need a personalized desktop, he adds, but in some corporate cultures, deployments that fail to accommodate this demand won't succeed.

The lesson here, says Gartner's Wolf, is that many different pieces of operational software, including management tools and desktop antivirus software, will need to be tied into your desktop virtualization solution, so selecting the right products is critical. "There will be a high exit cost" for making the wrong choice and then having to backtrack, "so don't rush into a bad decision," Wolf warns.

Touchstone: Holding off virtualizing clients for now

Steven Porter, CIO at Touchstone Behavioral Health, recently completed a virtual desktop infrastructure proof of concept with VMware View. "We were very pleased with the results," he says. But he has decided to wait until some hardware incompatibility issues are resolved before he moves VDI into production mode.

"There's no real cost savings," he says, noting that additional virtualization and Windows licensing charges add $300 per laptop to his costs. Over the first three years, he says, "it's about a wash" when compared to what he pays now to run Windows on each physical machine. "But you gain in security and convenience. The real win is in end-user satisfaction."

Users will benefit from faster provisioning of desktops -- or re-provisioning when things go wrong. Other gains include greater reliability, better security and support for devices the user brings to work.

Porter says he'd like to get out of the business of owning hardware, most of which is laptops used in the field by Touchstone's staff. Many employees have their own computers and use the company laptop only to access electronic medical records and email. "That's 30% of my annual spend. I could divert that to projects that make more sense from a productivity standpoint," Porter says. "A lot of people are carrying my laptop during the daytime and pulling out theirs at night. They'd be more comfortable with one machine of their own choosing."

The technical issue holding back the project is the incompatibility of a USB-attached signature pad that's used in the field. The VMware View Client sees it as a mouse, and although the signature pad's manufacturer offers a "clunky" workaround, Porter feels that's too much to ask of his users, and he doesn't want to replace the signature pads. So he'll wait for a real solution.

More importantly, users in the pilot weren't sold on desktop virtualization technology either, although they would rather use a computer of their own choosing -- something that VDI enables. "They were ambivalent," Porter says. He eventually plans to roll out the virtual desktops. But before doing so, he says, he'll build a case study to show users "where they'll start seeing benefits, and that it will make their lives easier."

-- Robert L. Mitchell

IT organizations often perceive the different options as competing solutions, says Gartner's Margevicius, but the technologies are actually complementary. One approach may be better suited than another for a given use case, but two or more technologies may also be used together to create solutions that more closely address the needs of specific groups of users.

For example, an IT organization might deploy a virtual desktop to the user with Microsoft Office installed in it, and deliver other programs onto the virtual desktop using application virtualization.

The user sees a unified desktop environment, while IT improves stability by avoiding application-induced conflicts.

How a hosted virtual desktop infrastructure meshes with the rest of your data center depends on what you already have for back-end infrastructure and what your plans are for your virtual desktops.

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Calculate the implications for IT infrastructure

IT organizations that have already been down the virtualization road with servers have a leg up. They should be able to leverage at least some of their existing license agreements, as well as management tools, network equipment, networked storage and other infrastructure.

Virtual desktop architectures, which transmit graphics as well as keystroke data and mouse clicks, can tax your network, says Slattery. "If you have a lot of branch offices or home users who don't quite have the network performance you need, that may guide your decision." On the other hand, if you already have a virtual server environment and the network to support it, you may not need to invest as heavily in new switches and other networking equipment.

"Storage is also a concern because you're moving off relatively cheap disk on the desktop to a back-end SAN," says Align's Mayers. "Your cost per gigabyte is increased."

Management tools are a still a work in progress, says Gartner's Wolf. "I ask clients, if they have to add another five tools to manage their virtual desktop environment, which ones are they able to take away that they used previously? Typically, the answer is none." The most popular tools may be able to plug into enterprise management frameworks from Microsoft, IBM and others. But the integration work is unfinished, Wolf says.

Antivirus software is another hidden cost, says Wolf. Installing traditional desktop antivirus software into each virtual machine taxes CPU cycles and disk I/O. While McAfee and Trend Micro now offer special-purpose virtual antivirus appliances, most IT organizations are waiting for the second-generation product before committing to it, Wolf says.

"The net result will be that you will be running fewer desktops on physical servers than you planned for, and you can imagine how that snowballs," Wolf explains. "That means more servers, more storage ports, and the cost of supporting virtual desktops can go up as a result."

In other words, if you're running fewer virtual desktops on physical servers than you had planned because of the antivirus software and other gear needed to support those desktops, that means you'll need more physical servers. But there's no rule of thumb for this in terms of X number of servers to support Y number of virtual desktops, because there are too many variables, such as the number of applications installed in the image.

Slattery is less concerned about management tools, storage and other infrastructure, which IT already knows how to deploy and manage efficiently. "The biggest challenges come down to licensing," he says.

Check your licenses

IT needs to factor in licensing costs for virtualization software and infrastructure management tools, but the wild card is what it will cost to migrate all of those Windows licenses off physical hardware and onto virtual desktops.

Whirlpool VDI strategy focuses on customer service

For appliance manufacturer Whirlpool, which is in the early stages of a VMware virtual desktop rollout to 18,000 employees, virtual desktop infrastructure is all about improved customer service -- specifically, improved reliability and flexibility. An aging population of 30,000 desktops with an array of disparate hardware and software configurations has been generating 30% of all trouble tickets.

"A lot of that goes away when you're talking about using virtual desktops," says CIO Kevin Summers. Further, employees will be more productive because their virtual desktop environments are more stable when hosted in the data center rather than on aging PCs. Because virtual machines can stay running or enter a suspend mode after the user logs out, the virtual desktop "boot-up" process is much faster. And having all of those virtual desktops reside in the data center should make patching and updates much easier, he says.

Infrastructure problems had to be worked out during the pilot. "We had problems with the [virtualization] software, and with applications. The key challenge we have had in the application space is virtualizing Internet Explorer," Summers explains. "We had to develop a strategy together with VMware to handle plug-ins for IE. That has added to the timeline."

Virtualization allows for greater flexibility in that users can access their virtual desktops from any desktop -- or even an iPad. "People want that flexibility, to be able to use their own personal devices sometimes," Summers says. When the rollout is complete, Summers expects 60% of all desktop users to have a virtual desktop thin client or a combination of thin client and a device that they bring to work.

Several hundred virtual desktops have been rolled out. "Within 12 to 18 months, we'll have 10,000 people on virtual desktops," Summers says about the rollout. The plan is to virtualize first using existing laptops and desktops as clients, and then gradually replace those with thin clients during the normal refresh cycle. "We're going to try to phase out a lot of the old hardware," Summers says.

-- Robert L. Mitchell

The total cost depends on your existing licensing agreement. Users already paying for Microsoft's Software Assurance for Windows get the rights to create up to four Virtual Desktop Access (VDA) images for a given user's Windows-based desktop, laptop or tablet computer.

"Any device covered by Software Assurance gets the grant rights. Others, such as thin clients, require the purchase of a separate VDA license," says Gavriella Schuster, general manager of Windows product development.

For users without Software Assurance or who want to use a thin client, an iPad or a device other than a Windows-based desktop, laptop or tablet, it's a different matter. "Microsoft does not permit the Windows desktop operating system to be licensed away from the physical machine," says Margevicius at Gartner. "It requires you to purchase a separate VDA license [per virtual desktop], and that's $100 per year" per virtual desktop. (Microsoft's RDS client licenses, required for XenApp, cost a bit less -- in the range of $75 to $85 for a perpetual license. This is because the user is sharing a single instance of Windows Server rather than running a full instance of the Windows desktop operating system, Microsoft's Schuster says.)

"Because it's delivered on a virtual machine, Microsoft charges more," Margevicius says. "This is a very sore point with Microsoft customers."

In response, Schuster points out that "the VDA license includes many more rights than a standard Windows license." And while Software Assurance requires that the user has purchased an OEM Windows license with the physical client device, VDA does not. Further, Schuster explains, the VDA license provides customers "with special use rights, and it gives them access to training and deployment services as well as the rights to the next Windows release."

This was a sticking point for Touchstone Behavioral Health, which does not have Software Assurance. Porter says he already pays for each Windows license twice: once for the instance that ships with every laptop, and once for his enterprise agreement or VDA license. He estimates total client licensing costs -- Windows and virtualization client software -- at about $300 per year per seat. He'd like to see concurrent licensing. "The vendors strong-arm me into buying more seats. They're nickel-and-diming me to death," he says.

But if you're doing only application virtualization, Microsoft's product in this category, App-V, can be fairly inexpensive because Microsoft makes it available through its Software Assurance license agreements. The typical annual cost in that scenario is generally in the range of $5 to $10 per seat, Margevicius says.

Licensing issues can also derail a client virtualization project if you outsource support of your desktops to a managed service provider, Accenture's Slattery warns. "Your vendor might not have envisioned this sort of solution, and that may delay you or cause you to reopen an agreement," he says.

Finally, a Windows 7 migration can change the math when it comes to incremental licensing costs, since you may have to buy new licenses anyway. "We have customers at Align who don't have Software Assurance who say, 'If I have to buy an operating system anyway to upgrade to Windows 7 and new desktops to support it, maybe that justifies looking into this,' " says Mayers.

And if you're also upgrading Microsoft Office, virtualization may make that upgrade process easier if you don't already have an efficient, automated software distribution mechanism.

Before embarking on a client virtualization project, IT can increase the chances for success by shrinking the application portfolio, says INX's Kaplan. "Do you really need five different versions of a spreadsheet program out there?" he asks. "Probably not."

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Rationalize your applications

The Co-operative Group's Cawson says the grocery chain's IT staff used AppDNA's AppTitude tool to evaluate the suitability of each of the company's 1,400 applications for virtualization. The tool also ranked the difficulty of consolidating or eliminating programs that had issues running in a virtual desktop environment. Some of the more difficult ones were dropped, and multiple versions of productivity applications, such as Adobe Photoshop, were consolidated.

So far, Cawson has packaged 200 applications for virtualization and discarded 100 others. The former are streamed into XenDesktop virtual desktops using App-V. Ultimately, Cawson hopes to cut the total application count by nearly half, to between 750 and 800.

As for the applications you do keep, be sure to check that your software vendors will support the products in a virtual client setting, INX's Kaplan suggests. Finally, going forward, he says, "make it an organizational requirement" that all RFPs sent to application vendors mandate support for desktop virtualization.

Build the business case and ROI

Expected savings on PC refreshes may be outweighed by the considerable investment you'll need to make to create a consolidated back-end infrastructure -- processing, network, storage -- to replicate what your users were doing on their local PCs. And while there are hard-dollar savings to be had from a VDI initiative, it very much depends on your current client and back-end infrastructure, whether you're up for a PC refresh anyway, and how well you manage the PC infrastructure you already have.

Even in applications where client virtualization technologies make sense, project scale can affect ROI. "Between 100 and 200 desktops is where you start seeing some of the savings," says Mayers.

Costs to implement a virtualized client environment can vary widely, depending on current infrastructure. But for an organization that already has an established virtual server environment and the infrastructure in place to support it, expect hosted desktop virtualization deployment costs to fall somewhere in the ballpark of $800 to $1,600 per desktop, Mayers says. That will vary, he cautions, based on your actual virtual desktop configuration, the server and storage systems used, and the tools chosen for antivirus, personalization management, backup and recovery, and other management tools.

Other consultants say that costs vary so widely that they couldn't even hazard a guess.

One thing almost everyone agrees on: Vendor ROI claims are grossly inflated. "Expect a three-year ROI at best," Wolf says. But there are real benefits -- and cost savings -- around the total cost of ownership for virtualized desktops versus that for full-on PCs. These savings come from IT process improvements and filling strategic needs ranging from security and compliance to bring-your-own-computer initiatives.

Michael Kamer, manager of technology integration services at St. Luke's Health System, says sales people pushed the idea that compared with the cost of buying new PCs, he could achieve operational savings of 40% with desktop virtualization, using a design built around XenDesktop. His own numbers, double-checked by a consultant, came in at about 9%. "So far, that has proved to be fairly accurate," he says.

"The ROI just wasn't there," says Porter at Touchstone. For his organization, the benefits of its VMware View pilot were about better security, faster provisioning of new users, and user self-service. "You've got to find those soft costs," he says.

Petroleum Pipe Co.: Virtualization offers remote possibilities

Oil industry service provider Petroleum Pipe Co. (PPC) rolled out application virtualization to address desktop support issues in office locations ranging from Dubai to Singapore and is now considering full desktop virtualization.

"The traditional approach with servers and desktops in each office just isn't practical for us," says group IT manager Chris Starling, because it's hard to find support expertise in locations like Iraq. So about one and a half years ago, PPC deployed Citrix XenApp to virtualize application delivery.

"Our biggest savings is on the staff who keep it running," he says. "Nothing is as frustrating as watching one of your guys walking around to machine after machine, fixing the same things. Virtualization cuts down on those issues."

But Starling had to overcome another limitation before moving forward. "In places like Kurdistan, bandwidth is very expensive," he says. To optimize bandwidth, Starling brought in a third-party tool, Veloxum for Citrix, to maximize the performance over the networks and on the back-end servers.

Starling also launched a desktop virtualization testbed using XenDesktop, which he'd like to use in the Dubai headquarters to eliminate desktops in favor of thin clients. But both desktop and application virtualization technologies face cultural resistance. "We're faced with questions such as, where is the server, and why isn't it next door to me?"

Users also tend to resist the idea of a plain vanilla desktop, so Starling is considering adding personalization to the nonpersistent virtual desktops, which spin up from a common, golden image. "At the end of the day, our users want to be individuals," he says. "We can't deprive them of that."

Staff in some countries also resent the idea of being dictated to by people in another country. Virtualization is something that has to be sold, not forced. So Starling sells the benefits, such as how easy it is to get back up and working after a device failure or service interruption.

-- Robert L. Mitchell

"It's not cost savings I'm going after," says Whirlpool's Summers. "What's driving this goal is improved service." Because of aging PCs and notebook computers, multiple configurations and a mix of software versions, boot times were slow and trouble ticket volumes were high -- about 30% of all calls were attributed to desktop issues. The move to VDI has helped to address all of those problems, he says.

Rent-A-Center's Chanani estimates that costs for his project will be higher for the first three years due to back-end expenses, but he expects that to even out because client devices will last longer. Client virtualization, he says, will reduce costs and increase shareholder value, because customer data never leaves the premises.

ROI also depends on how well the existing environment is managed. If the business buys expensive PCs and laptops every three years but has Microsoft Software Assurance and wants thin clients to replace the PCs, "you can show one whopping ROI," says INX's Kaplan. On the other hand, he says, "if you're using Altiris or some other push product in a well-managed environment and it works well, moving to VDI isn't going to save a lot of money."

Ease from pilot to deployment

After you understand the business imperatives, it's time to figure out the right technology. Do you need desktop virtualization at all, or is application virtualization enough? Should you follow the persistent VDI model, in which every user has a dedicated virtual machine, or follow a nonpersistent model, in which virtual desktops are spun up as needed from a common, standardized set of disk images? Do you need to add personalization to those nonpersistent images, and if so, will the basics offered by Citrix, Microsoft or VMware do, or do you need more sophisticated tools?

The answer may be "all of the above." Different user profiles dictate different technologies. Bring the products in, test them against your needs and expectations, and do a pilot, Accenture's Slattery suggests.

Summer says Whirlpool's VMware View pilot went on for 12 months before IT started rolling it out to 18,000 employees. He advises taking your time on both the pilot and deployment. "We had problems with the software, with applications and the network," he says. Since working through those issues, Whirlpool has rolled out the VMware View Client to a few hundred desktops and will continue as client hardware is refreshed. "In 12 to 18 months, we'll have about 10,000 people on virtual desktops," he says.

The pilot will also set the stage for selling users on the project. "You want users who like new technology, who will tolerate [problems] and generate positive buzz," says Kaplan.

While the pilot will give you champions of the technology among the user base, that doesn't mean you should skimp on training, Kaplan says. "In a lot of IT departments, the user walks in and sees a thin terminal on their desk and that's their introduction to VDI. You'd better have a strategy to sell it to users and get them excited about it," he says. He suggests talking about features such as the ability to "roll back" a desktop after a failure, and the ability to interrupt a desktop session at work, go home, log back in and pick up where you left off.

Rent-A-Center did video training. "That was a big hit for us," Chanani says. But he underestimated the sense of security that people feel knowing that their Word documents and other data reside on a physical device that's in their possession. "That's more powerful than I imagined," he acknowledges. "We still haven't gotten over that yet, even though the virtual experience looks and feels just like a Windows desktop."

Ultimately, the key to success lies not just in making the business case, but in creating a "business pull" for the technology rather than an IT push, says Summers. He stresses increased productivity through features such as faster boot times, greater reliability, faster recovery times, increased security and the ability to have almost instant access to the virtual desktop from any location or any device with an Internet connection. "That's our whole strategy," he adds.