"Live migration is probably the most important technology that Microsoft has added to Hyper-V in Windows Server 2008 R2."

That's the word from Windows IT Pro's Michael Otey, who goes on to explain how live migration works, what's so great about it, and what you need to make good use of it.

The beauty of live migration is that it allows you to move virtual machines between your Hyper-V hosts without incurring any downtime. Just offload your VMs, do your maintenance, then migrate them back again.

Before you get started, however, bear in mind the system requirements:

On the hardware side, you need two x64 systems with compatible processors. It's best if the host processors are identical, though it's not required. However, they do need to be from the same processor manufacturer and family--you can't perform a live migration when one host has an AMD processor and the other host has an Intel processor. Learn more about Hyper-V processor compatibility in the Microsoft white paper, "Virtual Machine Processor Compatibility Mode."

If you have even the slightest interest in Hyper-V, virtualization, and/or virtual machines, Otey's step-by-step guide is indispensable. Give it a look.