Weighing the pros/cons of desktop virtualization

Successful server virtualization deployments lead many IT managers to believe desktop virtualization would provide the same benefits. While that is partly true, companies need to be aware of how the two technologies differ, industry experts caution.

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"Desktop virtualization is a very different beast and should not be treated as simple enhancements to the server strategy," says Natalie Lambert, principal analyst at Forrester Research. "The drivers are entirely different and the environment will present new challenges to those experienced with server virtualization."

For instance, desktop virtualization doesn't offer the near-immediate cost benefits many cite with virtual server rollouts. And while virtual servers present new security and management challenges, many argue that in the desktop realm, virtualization improves security and manageability for IT departments. In addition, the sheer numbers involved can be strikingly different.

"IT managers could be taking on 500 virtual servers, and that is a lot, but it is nothing compared to 10,000 desktops," Lambert says.

According to industry experts and IT pros, there are some similarities and many differences between virtual servers and virtual desktops. (See related story, "No virtualization skills? Better get started.") Here we highlight key factors that could help avoid major headaches when moving virtualization to the desktop.

Complexity intensified

Most IT departments at enterprise companies have exponentially more desktops to support than servers, virtual or otherwise. The sheer volume of desktops should be one of the first criteria IT managers consider when making a move to a virtual platform.

With more than one billion PCs in the world, there's a huge opportunity for virtualization, but "all the requirements of the PC world need to be maintained as you migrate into the data center," says Mark Margevicius, vice president and research director at Gartner. "The desktop realm represents a lot more moving parts, considering all the uniqueness that happens on a PC needs to be maintained."

Server virtualization teams are unlikely to be responsible for the desktop infrastructure, beyond the servers that host the virtualization platforms. That means desktop groups need to rethink patch management, software distribution and other functions when applying them to a centralized system rather than a slew of disparate desktops.

"Desktop teams know how to manage 100,000 machines so the practices and policies are completely different. In the virtual realm the desktops come back to the server environment but cannot be thought of in the same terms," Forrester's Lambert says.

For Jake Seitz, expanding his company's VMware server virtualization deployment to include desktops was driven by compliance requirements and a move away from supporting desktop hardware. The enterprise architect at The First American Corp. in Santa Ana, Calif., says his group may be supporting less desktop hardware, but now they are responsible for maintaining "all these unique virtual machines." With 22,000 desktops, Seitz says the plan is to migrate 3,000 to 4,000 per year as hardware comes off its lease or as it fails – a plan that will help his team stay on top of the new virtual environment as well.