I encountered a similar problem on the HP/UX Version 3 server.  After the
conversion to Version 3, tape mounts were extremely slow (3-5 minutes +).  If
you did a SHOW THREADS command, you would see tasks awaiting mutex in routine
MMSAcquireAuto.  A PMR was opened with IBM.  I got a fixtest for the Version
3.1.2.0 release and the fix was incorporated into 3.1.2.1.  The problem was
associated with excessive checking of the drive list.  If you have a large
number of tape drives (we have 8 in a STK 9710), the problem is worse.

"Lehman, Leo" wrote:

> About 2 weeks ago we upgraded our ADSM server to Version 3.1.2.. We are
> running
> this on a RS/6000 (4.2.1) and attached to ADSM is a STK  9710  Tape Library.
>
> Since this upgrade we are having noticeable delays whenever a tape is to be
> mounted for processing.
>
> Examples  (1)Migration from diskpool to tape pool starts at 4:00 PM. tape
> does not mount until about 4:05.
>                  (2)Yesterday user went to do restore, data was on tape, had
> to wait about 5 minutes or more before
>                      ADSM issued a mount for this tape.
>
> Nothing has changed in our ADSM server option file or the 9710's firmware.
>
> Thank you for your time !
>
> Leo Lehman
> Hardware and Data Storage
> (717) 820-1625
> Lehmanl AT nabisco DOT com