KVM (for Kernel-based Virtual Machine) is a full virtualization solution for Linux on x86 hardware containing virtualization extensions (Intel VT or AMD-V). More Information here.
KVM is now native to RHEL/Centos and has replaced Xen in RHEL 5.4.
What i have seen so far has been pretty interesting, but I have barely scratched the surface of KVM’s inner workings.
Anyway, to clone a virtual machine you need to run the virt-clone command to clone the virtual disk. This automatically creates the virtual machine for you and registers it in virt-manager.
#virt-clone –original vm01 –name vm02 –file /vol0/vm02.img
Note that you do not need to tell virt-clone the location of the existing virtual disk. It figures this out on its own based on the name of the existing virtual machine.