Howtoforge posted a guide about virtualization with KVM on a Debian Squeeze Server
This guide explains how you can install and use KVM for creating and running virtual machines on a Debian Squeeze server. I will show how to create image-based virtual machines and also virtual machines that use a logical volume (LVM). KVM is short for Kernel-based Virtual Machine and makes use of hardware virtualization, i.e., you need a CPU that supports hardware virtualization, e.g. Intel VT or AMD-V.Virtualization With KVM On A Debian Squeeze Server