Your original email included "Win2003 clients".
If you are now discounting their participation and focusing on only
the AIX client sessions, then it's possible that they are using ACLs
(particularly for GPFS), where DIRMc considerations could be a factor.
In any case, why leave this a mystery when you can readily examine the
physical evidence, as per my last posting, and get a real sense of
what's going on in those sessions?  It's possible that collocation
values are contributing to this.

   Richard Sims

On Sep 24, 2008, at 4:19 PM, Schneider, John wrote:

Richard,
        Thank you for your reply.
        The clients I am referring to are AIX, as my original email
indicated.  Andy's explanation is a good one, and says the same thing
that the Performance Guide says.
        Neither explains the behavior we are seeing.  Resourceutil=10
should yield a maximum of 4 consumer sessions, and therefore a maximum
of 4 tape mounts.  So if maxnummp=4, then why are we still getting
the:

ANR0539W Transaction failed for session 163135 for node APLORA01. This
node has exceeded its maximum number of mount points.

messages? Are we the only site seeing this?  Am I just nuts, or is TSM
really working differently than documented?  (Or both)  I guess I will
just reduce the resourceutil parameter until the problem goes away,
and
just leave it a mystery.