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.
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.
Percentage relates to the total of all PC desktop shipments.
2011 -- 13.5 million seats -- 3%
2014 -- 34 million seats -- 7%
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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