Alan,
        As can be expected there is got to be a dozen different things to
look at.  However, from what you have said so far I would cut the maximum
number of concurrent session in half.  I found that when I get too many
concurrent session TSM thrashes.   I just started backing up desktops during
the day.  I backup 200+ desktops in about 2.5 hours and averages about 90GB.
My adapter is ATM but the desktop's network is fast Ethernet.  To get my
desktop window to work I did the following:
The clients are kicked by POLLING
The MAXSCHEDSESSION reduced to 25
The RANDOMIZE  set to 50
The MAXCMDRETRIES   set to 12
The RETRYPERIOD   set to 15 minutes
This spread out the start of the backups to the 1st 1/2 of the schedule
window, reduced the concurrent backups, but had the backups that didn't have
a session available to retry every 15 minutes for 3 hours.
Matt
PS; I am running TSM 5.1.5.4 on z/OS 1.1 on a 9672 x57.   My server backups
that are run overnight use multiple adapters.  I expand the concurrent
sessions to 50 for them and manage to get the 1st 100GB of 300GB moved in
about 3.5 hours.
Ask your network guys what the network is doing overnight or dialin and look
at CPU Utilization,  and the rate of the adapter TSO RMFMON, then PFK4 to
see the Mbytes/sec for that CHPID  (OSA-Es report as CHPID ID's)
 -----Original Message-----
From:   Alan Davenport [mailto:Alan.Davenport AT SELECTIVE DOT COM]
Sent:   Wednesday, February 12, 2003 10:46 AM
To:     ADSM-L AT VM.MARIST DOT EDU
Subject:        OS390 TSM Performance questions.

Hello,

        We're running TSM v5.1.5.4 on an IBM 20660A2 processor running OS390
v10. There is a 100Mbit, single port OSA card on the processor. We are
backing up 197 clients per night. MAXSCHEDSESSIONS is set to allow 116
simultaneous backup sessions. Our backup window begins at 20:00 and ends at
07:30 the next morning. We are seeing poor performance on our backups during
the window.  For example, one server that will backup in 6-7 minutes outside
the window takes hours to complete during the window. The TSM server has a
region size of 1280M and MPTHREADING is set to YES. Self tune buffer size
and TXN size is enabled. We are backing up to a 100GB disc buffer to an EMC
model 8830 drive array. On average we backup 30-40GB per night with a peak
of 75-80GB.

        I know there are much larger shops backing up many more servers out
there running OS390 also. What I would like to know is, on large shops, what
is your OSA configuration? Are you running multi-port OSAs and/or gigabit
cards? For comparison, I would also like to know how many clients you are
backing up per night. Where do you think the bottleneck is? Have you seen
similar problems and what did you do to help alleviate the problem? I am
fairly confident that TSM is not CPU constrained during the window. We
recently moved TSM to a higher service class with little effect on the
problem.  Do you feel we are saturating the OSA card?

        Any thoughts and suggestions would be greatly appreciated.

          Take care,
               Al

Alan Davenport
Senior Storage Administrator
Selective Insurance Co. of America
alan.davenport AT selective DOT com
(973) 948-1306