Server virtualization is widespread in large enterprise shops, but IT managers there have yet to warm up to another hot topic in IT: cloud computing.
A survey of mostly IBM System z mainframe users found that seven out of 10 respondents have deployed server virtualization, according to the user group SHARE.
The findings are similar to those of Data Center Decisions 2008 Purchasing Intentions survey, in which 61% of respondents said they planned to extend deployment of virtualization in 2008.
SHARE's survey also asked respondents about cloud computing and found that 85% had no plans for cloud computing or were unsure whether they would adopt it.Virtualization, cloud-computing adoption rates tell mixed story
The SHARE survey included responses from 388 IT personnel, ranging from system administrators to corporate executives. Most of the respondents were mainframe users, with 85% using z/OS and 51% using z/VM.
The survey found that all forms of virtualization –server, storage and network – are more common in large organizations than in smaller ones. For example, 78% of companies with 10,000 or more employees have deployed server virtualization, compared with only 63% of companies with 1,000 employees or fewer.
In a reversal of server virtualization trends, however, a growing number of smaller companies reported using cloud computing: 11% of companies with 1,000 employees or fewer, compared with 5% in companies with 10,000 employees or more.
"To some extent, this confirmed some of the anecdotal things we've been hearing," said Jim Michael, the vice president of SHARE. "It is the server virtualization option that is most advanced. Storage virtualization is coming along, and the others are beginning to be adopted at various levels. Cloud computing is starting to have an impact, but it's still early in the curve."Mainframe vs. x86 server virtualization
Virtualization has been a mainstay of mainframe and Unix server platforms for decades, but it's only the rise of VMware that brought virtualization down to the x86 world and made it wildly popular. Michael said the benefits of virtualization on big iron and on Intel-based servers are similar, namely workload consolidation, faster server provisioning and better reliability, thanks to workload mobility.
But Jim Vincent, a mainframer at Nationwide Mutual Insurance Co., said mainframe and x86 virtualization have some key differences. Nationwide was one of the first large organizations to broadly deploy virtual Linux servers on the IBM System z mainframe.
"In a mainframe environment, you can put hundreds of virtual servers onto a single mainframe," he said. But mainframe virtualization doesn't offer the same level of workload mobility between physical servers as does VMware. "What does the data center plan to do when they have to replace that mainframe or do any maintenance that requires the mainframe to be down for any extent of time?" he wondered. "Those are the kinds of things some folks didn't really think about when cranking out virtualization on the mainframe."
Conversely, Michael said a different challenge in the x86 world is securing virtual servers at the hypervisor level, something mainframers accustomed to the security of that platform don't worry about as much.
A challenge common to both platforms is the decision what to virtualize. At Nationwide, Vincent found that some homegrown applications were better left alone because it would have been too onerous to optimize them for a virtualized environment. In particular, Vincent said some applications hog too many resources when virtualized.
As for cloud computing, Vincent said that Nationwide is considering it, but that's about as far as it's gone.
"It seems like the cloud is now where server virtualization was six years ago," he said. "People are trying to understand where it might fit."
Let us know what you think about the story; email Mark Fontecchio, News Writer.
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