original source: http://unix.stackexchange.com/questions/8351/how-to-create-a-dupe-of-a-kvm-libvirt-virt-manager-vm
# You cannot "clone" a running vm, stop it. suspend and destroy
# are also valid options for less graceful cloning
virsh shutdown this.vm
# copy the storage.
cp /var/lib/libvirt/images/{this-vm,that-vm}.img