Desktop virtualisation: How to succeed
Rolling out virtual infrastructure across the enterprise is a lot tougher than you might think
By Robert L. Mitchell | Computerworld US | Published: 15:00, 04 May 2011
If you've already virtualised the servers in your data centre, desktop virtualisation 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)? We 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.
The gains you should expect from hosted desktop virtualisation projects are very different from what accrues from server virtualisation. While server virtualisation 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 centre.
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But that hasn't stopped some IT shops from exploring the options.
When it comes to hosted virtual desktops, many organisations 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 flavours and options. For example, you can choose a "persistent" desktop, where every user gets his own dedicated, fully customisable installation of Windows residing within a hosted virtual machine, or go with the more efficient "non-persistent" VDI model, in which many users' virtual desktops are spun up from a single, common cookie-cutter disk image.
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 organisation, says Steve Kaplan, vice president of the data centre virtualisation 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 centre 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 virtualisation'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 virtualisation strategies are often built around three drivers, says Gartner analyst Chris Wolf:
- Security. Client virtualisation lets companies meet compliance or regulatory requirements, since no applications or data reside on the local machine, everything is managed on the server side.
- Business continuity. If a client device fails, the user can log in elsewhere and pick up where she left off.
- Operational efficiencies. These include easier management of centralised 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 consumerisation of the client is exactly what St. Luke's Health System is addressing. The healthcare provider has a pilot under way that delivers a virtualised 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 clamour 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 virtualisation 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 virtualisation 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. "Virtualisation follows them around," he says.
The retail chain Rent-A-Center, for example, recently launched a desktop virtualisation 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.
Rent-A-Center's virtualisation 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 centre 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.
Some organisations 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 ageing 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 virtualisation vendor. Steven Porter, CIO at Touchstone Behavioral Health, uncovered just this issue during a recent pilot with VMware View. 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 centre, where it can be more easily managed. Vendors offer several variations on this theme.