On Wed, Jul 03, 2019 at 14:07:10 -0400, Roger Jin wrote: Generally we refer as 'base' to the image which has overlays, so you are here describing a 'commit' operation. Which image is the topmost overlay used by the vm? Libvirt currently does not implement these operations while the VM is shutoff because the difference of interactions beween qemu and qemu-img. As a workaround, you can either do the pull via qemu-img manually, or start the vm in paused mode (virsh start --paused), then do the blockpull and then 'virsh destroy' the VM. The filesystems would be never touched so 'destroy' should be safe in this case.