I looked through the thread and see no comprehensive answer so will try:
write pass shows number of times the tape gets written. You have two
options:
1. Defined volumes - once reclaimed (or "move data", "move nodedata" used)
the volume becomes "Empty" and next round pass begins. For defined volumes
you can see write pass number be 0, 1, 2, ....
When the volume is deleted from the pool this number is reset - it is
tracked for volumes only but not for libvolumes! Thus the number is
reliable if the volumes are never deleted from the pools.

2. Scratch volumes - upon reclamation the volume is deleted from the pool.
Thus the number is reset after each use and you cannot have the number
over 1. The number also cannot be 0 because the volume is defined to the
pool immediately before first write. Thus for the scratch volumes the
number is always 1.

Usually scratch volumes are used and "write pass" number is useless. But
this information can be tracked other way:
select volume_name,count(*) as "Usage count" from volhistory where
type='STGNEW' group by volume_name
This would work correct only if volume history is not deleted for STGNEW,
i.e. "del volh t=all" is not used.

Zlatko Krastev
IT Consultant






Laura Buckley <buckley AT STORSOL DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
17.04.2003 07:45
Please respond to buckley


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        Can the volume write pass value be used to track media 
life?


Hi,

I have a customer who must prove to a governing agency that they are
adequately tracking media life.  They are using AIT-3 media which SONY
says has a lifecycle of 30,000 uses and a shelf life of approximately 30
years.  So - in order to comply with their regulations, they must show
that they are tracking the uses.  Does the value in the field called
Write Pass Number in the volume record equate to what the manufacturer
considers "uses"?  I believe this to mean a complete write pass from
beginning to end of media.

TIA

Laura Buckley
STORServer, Inc.
buckley AT storserver DOT com