December 31, 2010, 8:59 AM — Four years ago, data center server utilization was just 18%. To put it another way, on average 82% of the server capacity in major data centers was underutilized. Given all of the emphasis on server virtualization in the last few years, you'd expect utilization to have increased sharply. But it hasn't. According to Gartner research, overall utilization is still at 18% -- and utilization of x86 servers is one-third lower at 12%.
One big reason: Server virtualization has stalled. Research shops and vendors have published numbers indicating that although most enterprises have stuck their toe into the waters of virtualization, they've hardly plunged in. A survey by ESG Research published in November showed that only 39% of the VMs currently deployed are in production environments; a survey earlier in the year by Prism Microsystems found that just 30% of production servers have been virtualized. Late last year, Gartner put the number of workloads running in virtual machines at just 16%.
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What's the problem? Talk to analysts and industry insiders about this issue and you'll here the phrase "low-hanging fruit" -- that is, virtualization built up quite a head of steam as IT consolidated and virtualized in-house applications like email, Web, and file and test servers.
All those applications have a few common characteristics: They are "owned" by IT and, although important, are not generally seen as mission-critical. "Ownership of the applications belongs to the business units; the cloud and virtualization flies in the face of that," says Bruce Milne, vice president of product management for CA Technologies. When Milne worked at Hyperformix (now owned by CA), he found that his customers were running important servers at just 5 to 10% of capacity.
Applications that haven't been virtualized -- such as order processing, financial transactions, and ERP -- tend to be I/O-centric. That means it's much more difficult for IT to monitor performance and availability problems that could develop when they run in a virtualized environment, says Len Rosenthal, vice president of marketing at Virtual Instruments.