As recently as perhaps a year ago, there was still some talk that server virtualization might turn out to be a load of hype. There's no doubt now that the technology is for real.

Info-Tech Research Group senior analyst John Sloan briefed a crowd of 300 at a recent VMware User Group conference in Canada, on the state of the virtualization market.

Sloan, a former storage analyst, has found his work come full circle - virtualization is dragging network storage with it into the mainstream. Storage has to be abstracted from the applications for virtualization to work. One reason the virtualization cart got before the storage horse: While network storage is a strategic consideration, virtualization is tactical. When a server refresh window comes up, companies are thinking virtualization as the default option. Abstract the storage from the application and you can move virtual machines from host to host, do dynamic provisioning, etc. So virtualization triggers storage networking.

"Storage consolidation and virtualization and server consolidation are two sides of the same coin," Sloan said. Still, he said, betraying his storage bias, "I'd like to see people build a foundation of storage first."

We have to change our perspective on hardware and software. Pre-virtualization, your disaster recovery scheme would involve mirrored systems with identical hardware and software. With the operating system and applications abstracted from the physical processor, virtual machines can be treated essentially as files. "It's not about the box anymore," Sloan says. "It's about provisioning."

Three rules to remember, according to Sloan: hardware is capacity to provision applications; software is alignment with business goals and objectives, the intersection between strategic and operational goals; and management of the virtualized utility infrastructure is the differentiator.

The popular wisdom is that the bigger and more complex the enterprise, the more likely a candidate it is for virtualization. Maybe so, said Sloan, but the size of companies embracing virtualization is coming down. More than half of companies with more than 100 employees are at least looking into server virtualization, and a healthy 35 per cent of companies smaller than that are, too. Above 500 employees, three quarters are evaluating, planning or have already deployed some virtualization. And while the 5,000-employee-plus category leads in the proportion of companies that have already deployed some virtualization (45 per cent), "some" is a key word. Large enterprise, on average, had only virtualized 11 per cent of their environments. Small and midsized businesses virtualized on average 67 per cent of their infrastructure. And, said Sloan, you don't see the real value of virtualization until a large proportion of your infrastructure is virtualized.

Like the beer commercial says: Thos who like it, like it a lot. Or perhaps those who do it, like it a lot. More than 90 per cent of survey respondents who deployed a virtualization project say it's met or exceeded their expectations.

VMware hasn't had any serious competition on the server virtualization front, but that will change. Microsoft's Hyper-V hypervisor is due to come out of beta imminently, but, said Sloan, "The most important feature of Hyper-V is that exists ... now, (Microsoft is) in the game." Hyper-V is missing many key features, including the critical live migration. Sloan predicts Hyper-V will mature and grow in acceptance in a parallel path to that of Windows Server 2008, reaching a critical mass in 18 to 24 months.

In the meantime, that leaves Citrix's Xen hypervisor to do the heavy lifting in terms of competition and pressure on licensing costs. But how many times has Microsoft come late to the game and proceeded to push the other players off the turf? "Microsoft has always done very well with 'good enough,'" Sloan said.