When Microsoft and XenSource made the announcement that the two companies would be cooperating on the development of technology that would provide interoperability between Xen-enabled Linux and the new Microsoft Windows hypervisor technology-based Windows Server virtualization, people immediately took to the Internet to try and describe their feelings as to what just took place. In reading many of these articles, I could almost imagine the scene in Empire Strikes Back when Darth Vader asks Luke to join the dark side. Was the announcement really that bad? Did it cause a disturbance in the force?

The announcement claims that the agreement between these two companies will provide a number of benefits for end users, specifically:

• Interoperability by design through collaborative development of two leaders in virtualization technology


• A flexible, high performance and more secure virtualization Xen-enabled solution with Windows Server "Longhorn," optimized to support heterogeneous software environments and a wide array of hardware


• Microsoft technical support for issues regarding interoperability with Xen-enabled Linux guest operating systems through the standard Microsoft technical support process


• Additional products from XenSource that enhance manageability, performance, and reliability based on the collaboratively developed code


• Microsoft support for Windows on XenEnterprise, available in Q3 2006

XenSource says the "agreement is positive for users of the Xen-based systems since customers of all sizes can freely deploy their guest operating system images interchangeably between Xen-based systems and Windows Server virtualization. The interface between the guest and Windows Server virtualization is the Xen Hypercall API, mapped to the Windows Server virtualization Hypercall API, so more and more people will use these systems resulting in better quality and more support."

Bob Muglia, senior vice president of the Server and Tools Business at Microsoft, said "Microsoft's commitment to customers is to build bridges across the industry with solutions that are interoperable by design." He continues, "Our work with XenSource, a recognized leader in open source virtualization technology, reflects that commitment and Microsoft's ongoing efforts to bring virtualization solutions to the mainstream and help customers progress toward self-managing dynamic systems."

eWeek did an interview Podcast with Christine Martino, vice president of Hewlett-Packard's Open Source and Linux organization, and asked about her reaction to the Microsoft-XenSource agreement. During the interview, she said that the agreement is a good endorsement of Xen, it's a realization for Microsoft to the importance of this technology, and the virtualization market. And any work that's done there, that's kept open-source friendly, is good for us. HP works with XenSource as well, and their goal is to be involved to help develop an industry standard open-source model. Martino believes Microsoft is being very pragmatic, and recognizes the draw that Xen has and the importance of that.

But market leader VMware wasn't going to just sit there and watch a rosy picture being painted for the masses to consume. They charged right back in the media with a 1-2 counter punch of its own, calling the agreement out for what they believed it to truly represent.

Raghu Raghuram, VMware's vice president of Platform Products, said "this is a one-way arrangement where Microsoft will allow Linux to run on future Microsoft hypervisors through translated calls to the hypervisor when Windows is controlling the hardware, but not the other way around. Under this arrangement, Longhorn 'enlightenments' will not be ported or licensed to run on a Xen hypervisor." He continues, "To achieve true interoperability and choice, it is in the best interest of customers to run their operating systems, including Linux distributions, on hypervisors that use open standards and do not have license lock-in to proprietary interfaces."

Contrasting Microsoft's approach, Raghuram says, "VMware is actively working with the Linux kernel community to develop an open interface so that the Linux kernel can run natively and efficiently on a choice of hypervisors. This interface would also be available to any operating system. It is notable that Microsoft's announcement is being made about a hypervisor whose first release is roughly two years away or more, and while the Linux hypervisor interfaces are still being discussed in the community."

The question then becomes, which side of the fence do you fall on? Is this agreement between Microsoft and XenSource a one-way street favoring Microsoft like VMware says? Or will this agreement actually help the open-source community like Microsoft and XenSource claim? I'd love to know what you think.

Posted by David Marshall on July 24, 2006 04:57 PM