Also, check your mount retention time for the device class.
I seem to remember that being an issue during
large restores with requested data residing on multiple tapes.
For some reason I recall the restore operation only using one tape
drive for the restore, even though there were other drives available
to mount tapes on.  I would think that if the restore required 3 mounts
it would mount all three tapes on available drives but that did not seem to
be the case.

I updated my mountretention to 0 and as soon as it was done with that tape,
it unloaded it and immediately mounted the next one.
Remember to put it back when you're done.
This is probably a hack so if someone has any input I'd be interested to
hear it.

I think the only way to get multiple mounts would be to multi thread your
restore.

Regards,

Denis L. L'Huiller
973-360-7739
dlhuillier AT pershing DOT com
Enterprise Storage Forms ->
http://admpwb01/misc/misc/storage_forms_main.html



                    Robin Sharpe
                    <Robin_Sharpe@B        To:     ADSM-L AT VM.MARIST DOT EDU
                    ERLEX.COM>             cc:
                    Sent by: "ADSM:        Subject:     Re: "Think time" 
between switching tapes during restore
                    Dist Stor
                    Manager"
                    <ADSM-L AT VM DOT MARI
                    ST.EDU>


                    01/15/2002
                    11:39 AM
                    Please respond
                    to "ADSM: Dist
                    Stor Manager"






I would guess the server is figuring out what tape to mount next.  Can you
measure server cpu% and i/o during that time?

Robin Sharpe
Berlex Labs



                    Jeff Connor
                    <connorj@NIAGARAM
                    OHAWK.COM>        To:    ADSM-L AT VM.MARIST DOT EDU
                                      cc:    (bcc: Robin Sharpe/WA/USR/SHG)
                    01/15/02 11:05 AM Subject:
                    Please respond to        "Think time" between switching
tapes during restore
                    "ADSM: Dist Stor
                    Manager"







Does anyone know what TSM is doing just prior to switching tapes
during a restore?

First our environment:

TSM for AIX V4.1.4.0
AIX 4.3.3 on an H80
Client being restored is a Windows 4.0 server sp6a
   two 700MHz xeon with 512MB RAM
TSM Windows client 4.2.1.15
100Mbit Ethernet nic and switch locked at 100Mbit full duplex
3494 with 3590 Fibre Channel attached drives using K tapes.

  The specifics of what we are seeing is:

1. Nothing else is running on the TSM server except our restore
    session.
2. The DSMC process, viewed through task manager on the
    Windows client shows 0 to 1% CPU and system idle 99%+
3. Q SESS from the admin CLI shows the restore session in a RUN state
    with send and recv byte counts not moving.
4. After the session sits in a RUN state for up to 5 minutes a state change
    for the session to MEDIAW occurs.  A new tape is mounted in a minute
    or less and the session continues.

So my question is, what is going on during that time between tapes when the
session appears to halt but says it's running?  Anyone else seen this
behavior?  It does not appear to be a client or server resource
shortage of any kind.

Thanks
Jeff Connor

Niagara Mohawk Power Corp