Hosting Virtual Desktops: Tips for a Successful Outcome

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.

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.

Weighing the Pros/Cons of Desktop Virtualization

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." [See related story.]

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. [See sidebar.]

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.

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. [See sidebar.]

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."

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.

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