Add extra error checking to make sure trying to create an existing
volume group does not result in a failure. The same counts for deleting
a non-existing volume group, and adding/removing volumes to/from the
volume group.
Signed-off-by: Niels de Vos <ndevos@ibm.com>
Register the volumegroup controller as part
of rbd controller server to serve the volume
group RPC spec.
Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>
