Microsoft Cuts Key Features From Virtualization Server

With shipping deadlines looming and the WinHEC conference just days away, Microsoft chief virtualization strategist Mike Neil has announced that several crucial features have been excised from Viridian, the virtualization component of Longhorn. Viridian is the codename for Microsoft's Windows Server Virtualization technology that will eventually be included in Microsoft's server package.

Three key features are getting cut due to time constraints: live migration, the ability to "hot-add" resources like storage, memory and processors, and scaling up to more than 16 processors.

Just last month, Neil talked up the team's unprecedented scalability goal of 64 processors. For now at least, Viridian will ship with support for only 16 logical cores.

BetaNews has some illuminating analysis:

A 16 logical processor limitation will restrict a Viridian virtual server to only four quad-core processors, which could effectively box it in within a 4P server. What's more, if you can't add processors and memory on the fly, as they become available, you can't subtract them either, which will probably mean that for virtual servers distributed across multiple physical processors, little can be done to rescue the VM if one processor goes down.