It's a feature which could be ubiquitous in more data centers if it could just get out of the labs: the ability to move running virtual machines between platforms with next-to-zero downtime. Now, it's being done cross-platform.

Up to now, the ability for a data center to move a running virtual machine between active processors while giving the user little or no visible downtime, has mainly been possible under a limited set of circumstances: The VM platform needs to be managed by VMware ESX, and the CPUs involved need to come from the same manufacturer.

Earlier this month, a collaborative effort between AMD and Red Hat broke through both barriers, with a technology demonstration of VMs running on prototype Red Hat virtualization software, successfully being moved between Intel Xeon and 45 nm AMD Opteron "Shanghai" processors.

"Right now with this platform, you can migrate between AMD and Intel, between different AMDs and different Intels, everything works," said David BenDavid, Red Hat's senior solutions architect, in a video jointly produced with AMD. Showing a running video being served over the Internet by an actively migrating VM from Xeon to Opteron, BenDavid suggested that this could be one way that data centers could replace old, previous generation processors without turning any active server images off, and without impacting network performance to any appreciable degree at any time.

AMD's demonstration comes just weeks after a strange, though perhaps not unusual, split decision on Microsoft's part. At a marketing event at its corporate headquarters last September, Microsoft's server and tools chief Bob Muglia gave a brief demonstration of the live migration of a Windows-based virtual server across the company's Hyper-V platform, which will be upgraded for Windows Server 2008 R2 to incorporate this feature.

But that demo came at the same time that Muglia had to point out that the R2 release was slated for 2010, meaning Microsoft's take on live migration was delayed once again. To try to quell some of the damage, Microsoft representatives found themselves actively downplaying Muglia's own demo, telling BetaNews and others that it only represented features that very few customers say they want anyway. One spokesperson went so far as to say live migration may actually be an obstacle to data center efficiency.

Curiously, however, a very similar sounding message came from -- of all places -- VMware yesterday, in response to AMD's and Red Hat's demo. In a statement to TechTarget's Bridget Botelho, VMware Chief Platform Architect Richard Brunner (a former Intel veteran) said his ESX platform is designed for stability and reliability, adding, "Attempting to make cross-vendor x86 instruction sets and features compatible in a VM for live migration puts this stability at risk, and so we have not pursued it."

So on both sides of the proverbial platform pond, the obvious need for cross-platform functionality does not bode well. It may be up to Red Hat and AMD to pull this one off together, and now it appears both virtualization leaders may have just given them an opening to do just that.