Microsoft Thursday released its Hyper-V virtualization server, which has been nearly five year in the making and is a major play in the company's march toward services-based computing.

Hyper-V, which was code named Viridian and Windows Server Virtualization, hit its release-to-manufacturing (RTM) stage and will be posted on the company's Web site Thursday. It also will be available via automatic update starting July 8.

Hyper-V is free to users with a Windows Server 2008 license.

Microsoft originally said Hyper-V would ship "within 180 days of the shipment of Windows Server 2008," which was February 27. Most experts had pegged August as the delivery timeframe, but in April Microsoft began to hint that the software would come in June or July. Regardless, the technology has been late in arriving given that it was originally slated for inclusion with Windows Server 2008.

Virtualization is one of the hottest technologies in corporate computing today, although many studies show only a small percentage of servers have been virtualized so far. Still Microsoft is entering a crowded field and can't afford any gaffs.

VMware is the dominant player and says it is ready for Microsoft's challenge. In addition, Citrix, Oracle, Red Hat, Sun and Novell all offer Xen-based virtualization platforms. Just last week, Red Hat introduced a new Linux-based hypervisor called oVirt that can fit onto a 64MB flash drive and boot on virtually any piece of x86 hardware.

"Microsoft knows a lot is riding on Hyper-V," says Rand Morimoto, a consultant with Convergent Computing, which helps companies implement virtualization and has some 20 Hyper-V customers with more than 100 virtualized servers deployed.

Late to the game

To underscore the importance of Hyper-V, Microsoft's incoming chief software architect, Ray Ozzie, has tagged virtualization as one of the foundation technologies for the company's software plus services platform that will define the next chapter in its history.

A survey conducted in February by Walker Information for IT services and product supplier CDW, however, found that users have not been waiting for Microsoft.

The survey showed that 35 per cent of respondents have already implemented server virtualization, 18 per cent are evaluating the opportunity and 9 per cent are making plans to implement within the next 12 months. That means many are already running or evaluating the platforms that will compete with Hyper-V.

But some users in the Hyper-V early adopter program say the software is making their initial skepticism fade away.

"With performance, so far so good," says Robert McShinsky, systems engineer for Dartmouth-Hitchcock Medical Center (DHMC). McShinsky runs 15 virtual servers on Hyper-V and 150 on Microsoft's current platform, Virtual Server 2005 R2.

"In our testing, Hyper-V has just blown away Virtual Server. We started to push higher transaction databases into it. We have a lot more flexibility around disk I/O. We also wanted some of the benefits of quick migration so we could provide service level one [support] by being able to move things back and forth for application availability and management."