For John Turner, desktop virtualization isn't the right move yet. The director of networks and systems at Brandeis University in Waltham, Mass., says his group evaluated the possibility of extending their successful server virtualization implementation to the desktop and the argument didn't stand up. For one, being a university it would be a challenge to "lock down" a PC image for the majority of students, faculty and others to use. And without solid support for streaming video across the virtual PCs, Turner says he couldn't sign on just yet.
"From a university perspective, we have such a diversity of functions and we can't dictate too much to the end users. And without gigabit to the desktop, performance would be poor," he explains. "We imagined replacing only computers that fail, stretching the refresh cycle, going back to dumb terminals, but we have to also provide what people want with a powerful operating system."
First American's Seitz agrees that many virtual desktops need to be cloned from one golden image, with some changes applied depending on groups. But the majority of desktops incorporate "Microsoft Office and some basic functionality because that is all they need," he says. While First American is using VMware VDI primarily because it represented "the most cost-effective option," Seitz is also realizing benefits not directly related to costs.
"The number of help desk calls drops substantially because they related to hardware and we threw that out, and business continuity plans are more easily implemented," Seitz says. "Auditors are happier that our data doesn't leave our data centers and go overseas. The end user on a virtual desktop only sees a representation of the data and not the data itself, which simplifies a lot of what we do."
Don't forget network, storage
IT managers must also look closely at network and storage requirements in their virtual desktop environment because if they don't, what is already an expensive endeavor will become too costly to continue deploying.
"Typically when doing an ROI against desktops, you don't factor in network and storage costs. You need to break that all down in a per-virtual-machine model," Seitz says. "But storage could be a big cost; shared storage is not cheap."
Storage is a lesson already learned by server teams deploying virtualization, says Andi Mann, vice president of research at Enterprise Management Associates. For that reason, desktop groups should depend upon the experience of their peers when considering storage. For instance, 5,000 desktops each with a 60-gigabit drive built-in could prove to be cost exorbitant. But by bringing those storage requirements back to the data center, Mann says, via thin provisioning and data deduplication, desktop teams will lessen their costs and optimize resources.
"Storage management is one of the biggest concerns about desktop virtualization. A lot of resources can be wasted if not managed properly," Mann says.
He adds that the network is another area of concern, thought it's not typically on desktop managers' minds. While Gigabit Ethernet is a standard for data centers, it has yet to be widely deployed to the desktop.
Determining network capacity and understanding if an upgrade is in order could help IT managers decide on virtual desktops, Seitz says. "The network needs to be able to handle aggregate traffic from many desktops to one location in the data center, so an upgrade from 100MB Ethernet to Gigabit might be necessary," he says.