Windows Virtualization Opened to Linux

Microsoft late Monday announced a partnership with open source virtualization company XenSource in order to offer interoperability between Xen-enabled Linux installations and the upcoming "hypervisor" technology coming to Windows Server Longhorn.

The agreement means that Microsoft customers will be able to run Linux virtual machines alongside Windows guests. A hypervisor serves as the core software that runs multiple guest operating systems, providing management and control from a central location.

Thanks to virtualization features included in the latest Intel chips, Windows guests can also be run inside Xen. Previously, operating systems had to be Xen-enabled to communicate with the hypervisor rather than the computer hardware directly.

The idea of virtualization is to maximize efficiency when one operating system alone doesn't fully utilize the ever-increasing processor power of today's computer systems. Such technology can also take advantage of high-performance computing clusters, and new multi-core chips from Intel and AMD.

Virtualization also abstracts the software from the hardware, meaning a guest operating system can be transitioned to another machine running the hypervisor in a split-second if any hardware problems arise. With electricity costs soaring, businesses have additionally begun to implement the technology as a cost-saving measure.

With Windows Server Longhorn, due out in late 2007, Microsoft is taking an approach similar to that pioneered by XenSource. In turn, the two companies will collaborate on virtualization development, and offer support to each other's customers.

But customers have a long wait to see the fruits of the partnership; Microsoft's hypervisor technology, known by the code-name Viridian, won't be available until six months after the launch of the next Windows Server.

"Xen-enabled guests will run seamlessly on XenEnterprise now, and, as a result of this agreement, Xen-enabled Linux guests will also run on Windows Server virtualization. XenSource will also deliver additional products based on the collaboratively developed technology, further expanding the value of the relationship," remarked XenSource CEO Peter Levine.

Microsoft currently supports Linux as a guest operating system within Virtual Server 2005 R2, but that product runs atop Windows and thus has overhead that affects performance.