This object identifies the source logic volume of the mirror.
The object identified by this index is the same object as identified
by the same value of h3cLvindex.
Note that an entry of h3cMirrorConfigTable can be created only when
the associated h3cMirrorDistributeTable's objects is ready or the associated
select policy is not equal to 'none'.
If an entry is deleted, the associated h3cMirrorDistributeTable
objects should be deleted automatically.