Comment 41 for bug 1578036

Hi Xiaojun,

Can you explain why it would fail trying to create a new snapshot on the backup service node? Is the design of "scaling backup service" forbidding backup service node from even connecting to the ceph cluster when the original volume is 'in-use' status? My basic understanding is that for original volume with 'available' status, backup service node does exactly that, ie, connecting to the ceph cluster hosting the original volume and placing a request for a new snapshot via "source_rbd_image.create_snap(new_snap)". So I failed to see the difference between "in-use" vs "available" state for a ceph/cinder volume when requesting a snapshot from backup service node.