Comment 6 for bug 1247998

Yes, the issue is that the rbd driver's clone_image() should return ({}, False) if it encounters a non-raw image. I think the best fix is to add the image type (whatever glance says it is) as another argument to clone_image(), and for rbd check that the type is raw, otherwise return ({}, False) so that the flow falls back to doing a full copy (with conversion) via copy_volume_from_image().