I would recommend doing basic troubleshooting.. check the TSM server
activity log around the time the backup window occurred (e.g. -> q act
startt=01:00). What was the TSM server doing if not backing anyone up? Was
it trying to contact the clients and failing to (there would be repeated
"contacting client blahblah" msgs if it was). Is there nothing there except
a "client XX missed backup window" at the end of the window?

Ditto check the dsmsched.log on some of the clients. What were they doing
around the supposed backup time? It should say clearly when they got their
last schedule and what it was.

Are your clients in prompted or polling mode? The reason for the missed
backups could vary depending on what mode you use. If polling, what was the
interval the clients poll at (default is 12 hours)?

By looking at the logs you should be easily able to determine if it was a
connectivity problem or if the clients simply missed their schedules due to
an error in timing. You should also be able to see if the clients are
receiving the schedules and what time they individually think they're
supposed to being their backups. Some basic troubleshooting goes a long
way..

Regards,

Gerald Wichmann
Senior Systems Development Engineer
Zantaz, Inc.
925.598.3099 (w)