A MNT$_DEVNAM item descriptor
appears in the item list in the middle of a series of item descriptors
that specify a single shadow set. You can construct a volume set that
contains one or more nonshadowed disks, as well as one or more shadow sets. However, when you use
the MNT$_DEVNAM item descriptor to specify the nonshadowed disk, it
must not appear between the MNT$_SHANAM item descriptor that specifies
a virtual unit and the item descriptors that specify the members of
the shadow set that the virtual unit represents.