Microsoft hopes the move will allow its Windows hypervisor and virtualization technologies to run Linux in the same manner that Xen does and in a way that is effectively comparable to what Linux and Xen can do together.Microsoft announced July 18 a strategic relationship with XenSource for the development of technology to provide interoperability between Xen-enabled Linux and Windows Server virtualization.
The move means that when the technology is available, those enterprise customers deploying Novells SUSE Linux or Red Hats Red Hat Linux will have two world-class virtualization solutions built to take advantage of all the things that Linux has to offer, along with the assurances around that, according to Bob Muglia, senior vice president for servers and tools at Microsoft, ahead of the announcement.
Enterprise customers want the Redmond, Wash., software maker to drive the industry forward, and one of the areas they care about is interoperability with their existing systems, from those that are legacy and proprietary to those running Linux.
"We are looking at ways where we can do a great job of interoperating with those other environments," said Muglia.
While Muglia declined to comment on how the technology developed between Microsoft and XenSource will be made available, he did say the goal is to make it "very competitive and appropriate."
No final decision has been made on how this joint technology will be licensed, but Microsoft is committed to making it available very broadly, Muglia said, adding that "this technology is certainly not being developed under the [GNU] GPL [General Public License], and there are multiple ways we can bring this type of technology to market and partner with XenSource and others in the open-source community to make it broadly available."
Microsoft also recognized the funda-mental trend in the server industry toward an industry-standard architecture and away from a proprietary architecture, and as that has happened, both Windows and Linux stand to be beneficiaries, Muglia said.
"Moving forward, as our hypervisor [code-named Viridian] and virtualization technology in Windows Server gets done, that has deep strategic long-term importance for us," said Muglia.
Microsoft started looking at what it would take to run Linux on its Virtual Server product some 24 months ago, supported that and had a number of customers using its virtual server product to run Linux.
Frank Artale, vice president of business development at XenSource, in Palo Alto, Calif., told eWeek that Xen is being incorporated into Novells SUSE Linux Enterprise 10 platform, as well as in upcoming RHEL (Red Hat Enterprise Linux) releases, and said that, from a technical perspective, Linux has a protocol through which it talks to the Xen hypervisor.
"One of the significant pieces of the work we have going on is to provide an adapter between the Xen hypercall API and the Microsoft Windows Server virtualization hypercall API, so there will be adaptation to allow existing Linux implementations that are Xen-enabled to run on the Longhorn Server that has been enabled with Viridian," Artale said.
In addition, specific optimizations will be added to optimize Linux performance as it runs on top of Longhorn Server "in the form of drivers to enable specific forms of I/O partitions, in particular, network and disk I/O," Artale said.
Cooking with XenSource
* Xen to be baked into SUSE Linux Enterprise 10, released worldwide July 17.
* Xen to be baked into RHEL Version 5 by the end of the year.
* XenSource cooked up a strategic relationship with Microsoft in July for the development of technology to provide interoperability between Xen-enabled Linux and Windows Server virtualization, due in 2008
Linux & Open Source 
