Comment 2 for bug 1869746

We discussed this bug today in Cinder's weekly meeting and got a lot of good feedback. See notes in [0]. The discussion also continued in the #openstack-cinder IRC channel.

There are many possible approaches to this problem, each with its own impacts and drawbacks.

Among the suggested solutions are:
a) have all backups created having the same project as the volume
b) have all incremental backups created having the same project as its parent (in that case it disappears from the user's view?)

Among the impact of such solutions are:
a) what happens to the backups after a volume transfer is performed
b) backups should be semantically separated from volumes. Coupling them together makes it similar to snapshots
c) quota consumption when someone else is taking backups on user's behalf
d) source volume or parent backup is deleted, but it is in another project, how it impacts the incremental backup and the data
e) what is the impact for backup drivers

This is very complex and needs more analysis, we will further discuss this.

[0] http://eavesdrop.openstack.org/meetings/cinder/2020/cinder.2020-04-01-14.00.log.html#l-111