Managing virtual machines

Computerworld - It started out as a way to save money when Gannett Co. was adding new servers back in 2002. Now, says Eric Kuzmack, IT architect at the McLean, Va.-based newspaper publisher, "we have a couple hundred virtual machines in our data center." Virtualization technology has increased IT staff efficiency by allowing virtual servers to be deployed in days instead of the weeks required to provision physical machines.

But as virtual machine technology moves out of development labs and into production server environments in large numbers, some administrators are finding that the growth of virtual servers is getting ahead of the tools available to effectively manage them.

Existing server-monitoring tools are increasingly aware of virtual servers, but most aren't yet sophisticated enough to interpret feedback in a virtual machine context -- much less act on it. "They don't take into account the particulars of virtual machines," says Frank Gillett, an analyst at Forrester Research Inc.

For example, a virtual machine may be running at 100% utilization but using only a fraction of the underlying server's resources. "Some of the things you monitor no longer mean the same thing," Kuzmack says.

"It would be nice if all of our standard tools worked in the virtual space, but they don't, and it doesn't look like they're going to anytime soon," says Norm Fjeldheim, CIO at Qualcomm Inc. in San Diego. He is evaluating tools targeted at virtual machine management to fill the gap.

For many organizations, identifying the root cause of virtual server problems and rectifying them remains largely a manual process. As the number of virtual machines in the data center increases, solving those problems in an automated way becomes more urgent.

Performance monitoring is just one aspect of virtual machine management. Other tasks include optimizing the mix of virtual machines that should reside on each physical server to achieve the best possible performance; automating virtual machine provisioning, load balancing, patch management, configuration management and fail-over; and enabling policy-based orchestration to automatically trigger the appropriate responses to events.

For some functions, such as patch management, existing tools work fine, says Paul Poppleton, a senior staff engineer at Qualcomm. In other areas, he says, "we're getting the best wins on the tools that take into account the fact that systems are virtualized."

Even organizations just starting virtual server projects can quickly run into management challenges. Once the decision is made to introduce virtual servers, the numbers can increase much more rapidly than expected because it becomes easier to procure new servers, says Poppleton. "Tack on 20% or 30% to what you planned on for growth, because it can really take off on you," he warns. Qualcomm has 1,280 VMware ESX Server virtual machines companywide that run a mix of Windows and Linux. About 850 virtual machines are running in Qualcomm's data center, with each physical server hosting an average of 10 virtual machines.