I've seen TSM use more than the MOUNTLIMIT when high priority tasks need to
be performed. But I question you're use of a VTS for TSM? There was just a
long discussion on this a couple weeks back. Applications that use the
entire media (DISP=MOD) like TSM and DFSMShsm are not really good candidates
for a VTS. Check out the archives to review the thread.
(http://www.adsm.org) When TSM wants to add on to an existing storage pool
volume, the existing data must be transferred back into cache in the VTS
before it can be appended. Then the 'new' volume has to be staged back to
real 3590 tape. The original location on real 3590 is now unavailable and
needs to be reclaimed. By doing this a lot, you are forcing the VTS to do a
lot of reclamation tasks. Plus the mount wait time to stage the data is
holding you up. Unles you write to a volume and mark it as read-only so TSM
won't try to append to it again.

Bill Boyer
DSS, Inc.