[libvirt-users] Blockpull behavior when interrupted

Hello, I use snapshot-create-as followed by blockpull when creating external snapshots of VMs. This works well, however I am curious about the behavior of blockpull after an unexpected shutdown (or SIGKILL). If a blockpull is in progress and an unexpected power loss occurs, will the VM continue to reference the backing file for the parts of it that have not yet been copied? Or, will will the disk image no longer be usable? Thanks, Andrew