
The virtualisation software is scheduled to ship next year as an update to Windows Server codenamed Longhorn. The server operating system itself is scheduled to ship by the end of this year.
The technology will no longer offer live migration, a feature that allows users to move virtual workloads to a different physical server as they are running. Users also will no longer be able to add storage, networking resources, processors or memory to running servers. Lastly, virtualisation will support only up to 16 cores, where the original design promised 64.
Pulling the features allows Microsoft to maintain its planned launch schedule, Microsoft's general manager for virtualisation strategy Mike Neil said in a posting on a company blog.
"Windows Server virtualisation is a core OS technology for the future, and we chose to focus on virtualisation scenarios that meet the demands of the broad market – enterprise, large organisations, and mid-market customers," he wrote.
Microsoft on 12 April was forced to delay the release of the Viridian public beta to the second half of this year. The final product has been promised within 180 days after the Longhorn launch.
Microsoft has blamed the earlier delay on the technology's inability to run well on systems with 64 processors. Microsoft at the time boasted that none of its competitors were able to match this level of scalability.
That statement however was incorrect. Sun Microsystems' Solaris operating system runs on servers with 144 cores and Novell's Suse Linux Enteprise Server 10 is running virtualized systems with 512 processors.
Scaling back to 16 cores even puts viridian behind VMWare ESX Server, which supports up to 32 cores.