Comment 8 for bug 1666450

And another issue is use this 0 size glance to create a volume, throw an error in cidner.volume.driver: def _try_execute(), I think this problem is caused by the 0 bytes glance above，and that's the log:
I use "rbd import --pool volumes --order 22 /var/lib/cinder/conversion/tmp_vlewa volume-67ae2b55-2279-4aa7-9b5e-653ad1488a17 --new-format --id admin --cluster ceph" import a volume is ok in container of cinder_volume, so this command is ok.