Virtualization: Ghosts in the Machine

Computerworld - What started simply as a way to consolidate older, out-of-warranty servers has quickly turned into a new infrastructure building block in Qualcomm Inc.'s data center. Virtual machines (VM) have risen to become a corporate standard for deploying and managing x86-based servers at the semiconductor maker. "We saved in the seven-figure range by not buying servers. Going forward, we're continuing to consolidate, and we're pushing everything we can into the virtual space," says Norm Fjeldheim, senior vice president and CIO at the San Diego-based company.
Server virtualization software allows applications to sit side by side on the same physical server, yet remain completely isolated, both from one another and from the underlying hardware. Applications within a VM see a dedicated operating system and server. Under the hood, however, a VM monitor allocates a share of the physical server's processor, memory and I/O resources to each VM.
Virtualization breaks the link between the hardware and the common requirement that applications run on dedicated servers. Adding a virtualization layer adds processing overhead that can range from an increase of a few percentage points into the double digits. However, most servers are significantly underutilized, so consolidation benefits are often dramatic.
At Qualcomm, which uses VMware Inc.'s ESX Server virtualization software, the ratio of VMs to physical servers has been as high as 18-to-1. Some 384 servers now run in VMs that reside on just 35 dual- and quad-processor machines. In all, 40% of the x86-based server applications at Qualcomm run on VMs, and that will increase to 50% in the next six months, says Paul Poppleton, senior staff engineer at the company.
As application servers continue to scale out, the proliferation of x86-based servers has outstripped the ability of administrators to manage them, says Nigel Dessau, vice president of virtualization solutions at IBM. Businesses today have seven times more servers than they did just 10 years ago, but the cost of managing them is nine times higher, he says. "Virtualization can start tackling that problem," Dessau adds.

Image Credit: Richard Downs