We are currently in a MagStar/9840 tape trial on our mainframe.  I have not put
any ADSM data on them (They are not attached to the LPAR that ADSM runs on).

  We have been backing up HSM data to both devices and have not seen any
problems.  We did have a microcode problem on the 9840 but that seemed to have
been fixed.   The 9840 using STK's 4:1 compress can get about 80GB on the tape.
The 3590 MagStar 3:1 Compression will get about 30GB on the tape.

DFSMShsm can only write appx 63GB to a tape at this time.  There is a limit to
the number of 16K block that DFSMShsm can keep track of. ( IBM is working on a
Fix  for this issue)

The question of what to put on the tapes is (IBM 30GB (soon to be 60GB) and IBM
direction is to have a 120GB cart), (STK 80GB)  is if you lose a cart how much
is lost.  and how easy is it to recover from.  Also a issue is multiple users of
the same tape.  Will users have to wait in line to get there data off the tape?


Jim Doll
CNJ  Rm330B 908-236-3492
Fax 908-236-3668