I had a similar problem on AIX, Sun and Linux.
I believe it may by network-related.
Re-starting "dsmc sched " fixes the problem.

On all my servers I re-start dsmc 5 mins before 
a scheduled start of operation using cron.
It is a band-aid solution but it works fine.

I would gladly hear from others..

Regards,

--
Mr Krzysztof Wozniak        ,-_|\      E-mail: K.WOZNIAK AT cowan.edu DOT au
Edith Cowan University     /     \      Phone: 61-8-9273 8026
Churchlands WA, 6018       $_,-._/        Fax: 61-8-9273 8000
Australia                       o


-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Christoph Pilgram
Sent: Wednesday, 12 May 2004 2:36 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Scheduler stops

Hi all,

For the second time now I have the problem, that suddenly the server's
scheduling service stops (in the mid of the night). I can't find any
message in the actlog and I don't know where else to look. All schedules
go to missed, in the client-Sched.log no message apears.
Last time I restarted the server and all was ok.
Tsm Server Version is 5.1.7.3 on an AIX 5.1

Thanks for any help to find out what caused the stop of the scheduler.

Chris