The Devilish Details of Desktop Virtualization
Slow from the Starting Gate
Despite all the buzz around desktop virtualization, there are signs of tepid adoption. In a recent survey conducted by sister publication CIO, only one out of four respondents was using desktop virtualization; one in five said it would be a year to three years before they'd deploy the technology; and 37 percent said they weren't interested at all.
Why all the hand-wringing? The fact is, desktop virtualization has a few technical blind spots that it still needs to cover. Graphics and streaming video don't work well on a virtual desktop without significant (and costly) network upgrades. "If you have high-graphic apps, this is going to be a kludgy environment to work in," Wilson says.
Certain applications also don't run smoothly on a virtual desktop, while some software licensing even forbids their use. "There are vendors selling applications who still want to resist," says Hiltz. "Vendors play with licensing models to squeeze more dollars out of you. I can't run Bloomberg on a virtual desktop based on the language of the licensing, even though technically I could."
Both Hiltz and Wilson worry that virtual desktop users will drain datacenter resources. Part of the problem is that users feel resources are unlimited in the virtual desktop model. Another issue is that management tools are not yet up to par, in terms of controlling CPU and memory usage for every employee. "I'd like to be able to throttle a user down," says Wilson. "While vendors say they have this ability, that's not really true yet."
Desktop virtualization adopters say these concerns aren't even the toughest hurdles when deploying the technology. They point to the need for massive infrastructure upgrades that wreak havoc on ROI, resistance from managers who are wary of hitching workers' productivity to a live Internet connection, and pushback from end-users who don't want to lose control of their workspaces.
Sweeping Infrastructure Upgrades
Wilson's infrastructure upgrades included a retooling of his network's points of failure. He used to have two T1 lines at every location, yet twice a year, AT&T would go dark and take out both of them. This wouldn't work in a virtual desktop environment, where "our base assumption is that you will always be connected," Wilson says. "Generally speaking, if you aren't connected, there's very little you can do anyway. Maybe you can write a Word document or work on an Excel spreadsheet, but even then you'll likely need to connect to a file server."
And so Wilson replaced a dedicated T1 line with cable or DSL (depending on the location) and added a Cisco router. Now he says he has three levels of redundancy on different technologies. Also, Wilson added 10 quad-core Dell servers running Citrix XenApp (formerly Presentation Server).
Lifetime installed a powerful MPLS (multiprotocol label switching) mesh network to accommodate the fast transfer of images its engineers needed to work on over thin clients. "Since virtual desktops are mostly used for WAN applications, make sure that your bandwidth and, more importantly, your latency are as low as possible," advises John Bowden, CIO at Lifetime.
Fast storage is another important factor for reducing latency. Fortunately for Natixis, the company had just bought high-end storage from EMC for its SAN. "Reliable, fast storage is key," says Florent Soland, manager of Windows services and virtualization at Natixis. "If you don't have it, it's going to take a lot more time to provision a workstation, and the end-user performance will be very bad."
Infrastructure upgrades throw a monkey wrench into the ROI that desktop virtualization was sold on. Add up the expense of new SAN storage, servers, virtualization software, a connection broker, and thin clients, among other costs, says Soland, "and it's more expensive to roll out 100 workstations in a virtual desktop infrastructure than 100 desktop workstations today -- we're still not there yet."
Au contraire, says Wilson. The reason ROI suffers, he says, is that most companies transition only a part of their workforce to virtual desktops. Indeed, Natixis plans to move 80 percent of its workforce to virtual desktops over the next couple of years. Lifetime's target is only 20 percent. This means they must support two computing models, contends Wilson.
"If you do this piecemeal, then you're only adding another layer and making the stack deeper and more complex," Wilson says. "The key is to deploy this strategically across the board." (To be fair, Natixis cites desktop virtualization concerns, such as licensing and apps that don't work well on virtual desktops, as barriers to a wholesale transition.)