Only in ROLLFORWARD mode. In NORMAL mode the log is used to hold the current
transaction(s) and when they are committed to the database are removed from
the log. He doesn't indicate what mode he's using.

If this is the only thing the TSM server is doing at the time, a single TDP
Informix backup, then I would look to see what the backup is doing. Maybe
expiring a lot of backup objects? He also doesn't say whether this has
worked and then after a while received this error, or that it just never
worked without getting the log full messages. Depending on the size of his
DB, I would concider increasing the LOG space anyway. You don't want your
important backups to fail because of a log full problem.

Bill Boyer
DSS, Inc.