It seems to be possible that the UUID was found, but the name is not
set. Checking on UUID makes the CreateVolumeGroup operation more
idempotent.
Signed-off-by: Niels de Vos <ndevos@ibm.com>
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>
