Hello Folks
 Please remember that backup storage pool is always an incremental.
It will only make a copy of a file (version of physical file) that was not
present in the
primary pool at the time of the last back up. So running backup stg on a
primary pool
for the first time will make a copy of all files present in the pool. The next
backup of this
pool will only make copies of new files (versions) since the last backup was
done.

 Regards
  Daniel Curtis ADSM level 1 support