Hi Everyone!

We decided to share our precious IBM3590 tape devices
in our IBM3494 tape robot between
the two different ADSM Servers we are running under AIX.

To do so we have both servers on one SP2 node with all six
drives defined to each of the ADSM servers.

The good news is that both servers have at their disposition
now upto six tape drives what is more than they had before
when the servers were on different nodes and there was a strict
separation of devices: 4 drives for one and 2 drives for the other.

The bad news is that under load situations - one server has serveral
tape mounts - the other server has difficulties to get a drive, although
there is at least one empty and not used.

Even reducing mountlimit in devclass and removing drives
 in one server will not immediately give one drive to the other
server. It takes typically some 20 minutes waiting for mountpoint
before the actual mount occurs.

Can somebody enlighten this situation for me ?

All I see with "show library" are parameters like
busy=0, online=1,polled=0
with all combinations of zeros and ones,
without insight under what conditions some "waiting for mountpoint"
will eventually come to mounting a volume.

Do I have any possibility to influence the interaction between the two servers?
Give perhaps different priorities to different tasks ?
What about Version 3, any changes ?

Thank you for listening
Matthias Feyerabend

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Matthias Feyerabend            phone:    (49) 6159 71-2519
Matthias Feyerabend            phone:    (49) 6159 71-2519
GSI, Darmstadt                 internet: M.Feyerabend AT gsi DOT de