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Microsoft has pushed back the release of the first public beta for Windows Server virtualization, code-named Viridian, from the first half of 2007 until the second half of the year so that it can meet its internal goals for performance and scalability.

Viridian is Microsoft’s Windows hypervisor technology that will run beneath the operating system and manage resources for multiple virtual machines.

But Microsoft is way behind its Linux competitors on this front, as Red Hat and Novell’s SUSE have both already integrated the Xen hypervisor technology into their server products.

“We still have some work to do to have the beta meet the ‘scale up’ bar we have set. Also, we’re tuning Windows Server virtualization to run demanding enterprise IT workloads, even I/O intensive workloads, so performance is very important and we still have some work to do here,” Mike Neil, the general manager for Microsoft’s virtualization strategy, said April 12.

Click here to read more about Microsoft’s Windows hypervisor technology.

But Viridian is still scheduled to be available within 180 days of the release of Windows Server “Longhorn,” which remains on track for beta 3 by the end of June 2007 and release to manufacturing in the second half of the year, he said.

The release of Virtual Server 2005 R2 service pack 1 has also been pushed back a quarter and will now ship by the end of June 2007, but Microsoft customers and partners will be able to download and use a Release Candidate version of the product by the end of April.

The second beta for Virtual Server 2005 R2 SP1 can be downloaded here.

Virtual Server 2005 R2 SP1 required additional time to test the three new operating systems for which support has been added: SUSE Linux Enterprise Server 10, Solaris 10 and the recent CTP build of Windows Server “Longhorn,” Neil said.

To read more about how Red Hat accused Novell of being “irresponsible” about Xen, click here.

In a blog posting, Neil stressed that Windows Server “Longhorn” remained on schedule, saying that “Iain McDonald and team are doing a great job delivering the next-generation Windows Server operating system, which includes features like TS Gateway, Server Core, Network Access Protection, IIS 7.0, new server manager and failover clustering improvements, to name a few.”

All this work was designed to ensure that Longhorn Server delivered a safer, more-secure infrastructure and simplified administrator tasks, he said.

Will Longhorn Server and Windows Vista SP1 ship together? Click here to read more.

The product was being designed to scale across a far broader range of systems than the competition, and to scale up to 64 processors, “which I’m proud to say is something no other vendor’s product supports. We are also providing a much more dynamic VM environment with hot-add of processors, memory, disk and networking as well a greater scalability with more SMP [symmetric multiprocessing] support and memory,” Neil said.

Some partners have also been testing a private beta version of Windows Server virtualization since December 2006, and Microsoft planned to continue to rely on their input as it headed towards the beta milestone, he said.

Microsoft also planned to provide guidance on how customers could add Windows Server virtualization to their systems running Windows Server “Longhorn.”

The service pack for Virtual Server 2005 R2 required additional time for the testing of three new operating systems for which support has been added: SUSE Linux Enterprise Server 10, Solaris 10 and the recent CTP build of Windows Server “Longhorn,” Neil said.

Read more here about why Microsoft decided to make Virtual Server available as a free download.

“An interesting point here—in less than one year we’ve seen more than 15,000 downloads of the Linux add-ins for Virtual Server 2005 R2, which indicates strong interest to consolidate Linux workloads on Windows Server,” he said.

Microsoft had also made enhancements with Virtual Server R2 SP1 that allowed it to scale on systems with more memory, up to 256 GB, and more cores—64 virtual machines on 32-bit Windows Server hosts and 512 VMs on x64 Windows Server hosts.

“And we’ve added support for hardware-assisted virtualization in the form of Intel VT and AMD-V. The team is also very proud of their delivery of Virtual PC 2007 and the interest in the product, with over 1 million downloads in the first 38 days,” he said.

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