[libvirt-users] Migrate VM's to different storage pool?

I am searching for directions for using live block migration to copy running vm's to a different storage pool. Example: VM1 running on Host1, the image(s) for VM1 are stored in /var/lib/libvirt/images. I'd like to copy the disk image(s) that VM1 is using to /nfs/images. Without stopping/pausing/powering down the VM. Do you have any examples or documentation of how to accomplish this process? Regards, Jamie Ian Fargen