Comment 8 for bug 888649

Yes, when I make that change the operations I'm doing work as expected.
That is, when I try to delete a volume that is referenced by a snapshot,
the volume driver detects that the volume is busy and leaves it in the
'available' state. I can continue to use the volume and the snapshot,
and I can subsequently delete the snapshot and then the volume.

The only observation I have is that euca-delete-volume returns success
when I try to delete the volume referenced by a snapshot. We think this
is acceptable.

In fact, I think that it's not possible to pass an error status back
from the nova-volume driver, through nova-api to the cli. So the only
way an error status could be returned to the CLI is if nova-api detected
the busy condition and didn't sent the request to nova-volume in the
case where the volume is being referenced.

But, we would not like nova-api to stop the delete request being sent to
the driver. Because we are developing a nova-volume driver that will
support the deleting volumes that are referenced by snapshots. We see
valid use cases for this and expect that other development groups would
too.