The development of such a bridge would allow Microsoft partners and customers to deploy and run Xen-enabled Linux guest operating systems on the Longhorn's "Viridian" virtualization engine, which is slated to become available for Windows Server in the first half of 2008.
The move also enables Microsoft to position its virtualization server code, due to ship six months after Longhorn, as suitable for a variety of hardware platforms and heterogeneous environments--a key requirement as the Redmond, Wash., software giant and XenSource prepare to take on virtualization market leader VMware.
More important, Microsoft has pledged to offer basic technical support for interoperability problems that occur when running Linux virtual machines on the planned Windows virtualization hypervisor.
Though this latest deal between Microsoft and XenSource will help customers run Novell, Red Hat and Virtual Iron Xen-based virtual machines on the Windows platform, it also will give XenSource an advantage over those rivals as well as VMware, whose hypervisor supports Linux and Windows environments. For Windows customers with Premier-level support agreements, for instance, Microsoft will offer "commercially reasonable" efforts to address potential issues with Microsoft software running on XenSource's upcoming XenEnterprise platform.
At LinuxWorld Expo in April, Microsoft and XenSource--a Palo Alto, Calif.-based commercial startup that sprung from the open-source Xen project--announced a deal to provide interoperability between Xen and Microsoft's Virtual Server platform, which will be replaced by Viridian. As part of that arrangement, XenSource licensed Microsoft's Virtual Hard Disk format so its customers could import and manage virtual machines created on Virtual Server.
Ian Pratt, Xen project leader, said the latest deal will benefit all Xen users. Novell on Monday shipped its first Xen-based Linux distribution, SUSE Linux Enterprise 10, and Red Hat plans to release its Xen-based upgraded Linux platform later this year.
"It really shows how far Xen has come, from research prototype in the [Cambridge] University to a virtualization standard that is now even going to be supported on Windows," Pratt told CRN in an e-mail. "Heterogeneous OS environments are likely to be the norm in the future, and having the ability to run Windows on Xen and Linux on Viridian gives flexibility and choice to users."