Comment 6 for bug 1627147

The issue is the same as https://bugs.launchpad.net/glance/+bug/1792710.

In every case when Glance use RBD and client upload image from non-RBD source Glance will use resize-before-write.
When you need to upload large images or create large instance snapshots from non-RBD ephemeral storages it becomes a real problem.

As Stuart suggested in comment to the patch set, maybe optional size field should be added to the json during initial create image POST request?
Another possibility I can think of is to reuse min_disk field, since RBD stores image in raw anyway.

Would be happy to assist anyone interested in fixing this bug, but can't handle it alone.