Microsoft has delayed the release of two key virtualisation components.

The release of the public beta for Viridian, the virtualisation technology that is being built into Windows Server codenamed Longhorn, has been pushed back from the first half to the second half of this year. Microsoft also will delay the release of Virtual Server 2005 R2 service pack 1 from the first to the second quarter of this year, Mike Neil general manager for Microsoft's virtualisation strategy wrote on a company blog.

He stressed that the delay will have no impact on the beta 3 release of Windows Server Longhorn. The third and final beta is due out in the first half of 2007 and the final product has been promised for the end of this year. Viridian will be made available as an update with 180 days after the Longhorn launch.

Microsoft wasn't satisfied with the performance and scalability of Viridian on servers with multiple processors, Neil explained in the blog posting.

"We still have some work to do to have the beta meet the 'scale up' bar we have set. Also, we're tuning Windows Server virtualisation to run demanding enterprise IT workloads, even I/O intensive workloads, so performance is very important and we still have some work to do here," Neil wrote.

He also claimed that Windows Server virtualisation will be the only application to support up to 64 CPUs.

Neil's claims about reaching new heights in the number of supported CPUs seems at odds with reality.

Novell's Suse Linux Enterprise Server 10 scales up to 1024 CPUs, although the largest production system today has a 'mere' 512 CPUs, a company spokesperson told vnunet.com. The operating system supports the open source Xen virtualisation technology. 

Solaris 10 too offers virtualisation support. The largest system that it ships on is Sun Microsystem's E25k server, featuring 72 dual-core SPARCIV+ processors.

The release of service pack 1 for Virtual Server 2005 R2 is delayed because Microsoft needed to test last minute additions of support for Solaris 10, Suse Linux Enterprise Server 10 and the latest build of Windows Server Longhorn to run as guest operating systems.

The update also will introduce support for virtualisation accelleration technologies that AMD and Intel have built into their processors.