Microsoft's shock move to embrace Linux could have wide-reaching impacts on the virtualisation market and Microsoft's rival VMware, said an analyst.

By allowing greater ability to run Linux on the Hyper-V virtualisation platform, Microsoft is making a compelling case that it could be the virtualisation vendor of choice for consolidation of Windows and Linux applications, said Gartner analyst George Weiss. Microsoft still lags behind VMware in enterprise features such as live migration.

But once Microsoft proves itself "good enough" in terms of functionality, many customers will be intrigued by Hyper-V as a lower-cost alternative to VMware, Weiss said.

"Windows with Hyper-V can be a good consolidation story for running Windows and Linux applications," Weiss says. The ability to take over more of the world of both Windows and Linux applications, which is what VMware has been doing, should help Microsoft in its battle against VMware."

Gartner's research shows that VMware still holds 80 percent to 90 percent of the x86 hypervisor market, according to Weiss.

Microsoft's big Linux push involved the submission of driver source code for inclusion in the Linux Kernel, which will provide the hooks for any distribution of Linux to run on Windows Server 2008 and its Hyper-V hypervisor technology.

Hyper-V's support of Linux-based guest operating systems was previously limited to several versions of SuSE Linux Enterprise Server. Microsoft provided integration components and technical support to customers who wanted to run SuSE Linux.

VMware also supports Linux, but Microsoft's move to submit code to the mainline Linux kernel could give Microsoft a leg up. VMware had already "certified kernel mode para-virtualization drivers but administrators have to install them separately because they are not part of the mainline Linux kernel."

With this latest move, Microsoft is pitching Hyper-V as one-stop shopping for both Windows and Linux virtualisation.

"The question becomes am I going to pick multiple versions of virtualisation technology; one for each operating system or workload, and if I do that, will I get the benefit that I need?" says Sam Ramji, Microsoft's director of open source technology strategy. "Or can I pick one virtualisation technology, one management technology and have one set of skills to support that whole infrastructure regardless if it is Unix, Linux or Windows running on top of it." VMware has not yet offered a response to the Microsoft Linux move.

Weiss expects VMware to play down Microsoft's announcement, and point out that it still has the most advanced technology in virtualisation management.

"I think VMware will try to downplay it as not significant, that they have already been there and done that, and they have the most market share and the market share comprises not only Windows but also Linux," he said..