DEL VOL XXXX will only work on an empty volume, if the volume still contains
data the DISCARDDATA=YES must
be added in order to remove this volume. The DEL VOL command REMOVES THE
REFERENCES FOR ALL OBJECTS
ON THAT VOLUME AND ANY COPY POOL COPIES OF THAT OBJECT FROM THE DATABASE. The
information is lost.

UPD VOL XXXX ACC=DESTROYED will mark a volume as destroyed, if this is a
primary stg vol and a copy of files on this
volume reside on a copy pool volume then ADSM will attempt to use the copy pool
volumes if the object is needed.
This status also allows the volume to be restored from the copy pool because
the references to the stored objects are not
removed.

Basicaly the DEL VOL is for ever and the UPD is a chang in status that can be
reversed at any time.

 Regards
  Daniel