Red Hat's KVM play should give Citrix and VMware pause

When I heard last week that Microsoft and Red Hat would cooperate on Xen virtualization, I knew the Linux leader's long awaited KVM strategy would be right around the corner.

It's no secret that Red Hat has chosen KVM in the Linux kernel over Xen as its long term virtualization engine. The Linux giant acquired Qumranet and its KVM, SolidICE/SPICE and management technologies last quarter and announced it would be the foundation for its next generation virtualization platform.

But yesterday we got more specifics on how Red Hat plans to take the transition from Xen -- the first major open source virtualization hypervisor it supported - to KVM, the Linux Torvalds backed v-engine that is incorporated as part of the Linux kernel.

Red Hat will deliver a new lightweight client hypervisor and virtualization management platform for servers and desktops over the next three to 18 months, with the first product appearing in mid 2009.

More importantly, Red Hat issued its war plan against Xen.

Red Hat, for instance, said it will continue to support Xen for the lifetime of Red Hat Enterprise Linux 5 but following that it would provide tools and services to enable customers to migrate from Red Hat Enterprise Linux 5 Xen deployment to KVM.

And it sought to define KVM's superiority over Xen. Red Hat said it will be "the only virtualization vendor leveraging technology that is developed as part of the Linux operating system."

That has to give Xen vendors and customers some pause.

Citrix has already stated plans for a lightweight client hypervisor and chose to debut yesterday a free version of its XenServer to steal thunder from Red Hat and position itself as the only viable open source virtualization engine eligible to take on VMware.

Red Hat, for its part, stepped up to remind the market that Xen is not the only open source hypervisor and that rival KVM is the only engine that will be backed long term by the industry leading Linux distribution provider and the creator of Linux himself.

The Citrix-Red Hat open source virtualization battle is closer to beginning (Red Hat need to ship product to fire the first real salvo, after all). This will give customers real choice in the open source virtualization space and delivers on the true promise of open source.

Now that should give VMware and its customers pause.