# Abort any failed/finished block operations:
$ virsh blockjob vm vda --abort
# Undefine a running domain. (Note: Undefining a running domain does not _kill_ the domain, it just converts it from persistent to transient.)
$ virsh undefine vm
# create a destination image with the original backing file and matching size of the instance root disk.
$ qemu-img create -f qcow2 vm_copy --backing_file=backing_file --size=root_disk_size
#Invoke 'virsh blockcopy' (This will take time, depending on the size of disk image vm1):
$ virsh blockcopy --domain vm vda vm_copy --wait --verbose
#Abort any failed/finished block operations:
$ virsh blockjob vm vda --abort
#Define the guest again (to make it persistent):
$ virsh define vm
#From the obtained new copy, convert the QCOW2 with a backing file to a qcow2 image with no backing file, then upload to glance:
$ qemu-img convert -f qcow2 -O raw vm_copy vm_convert