After taking a glance at this thread, let me put a thought to mind. If you want tsm_drtape_onsite script to run regularly - you have several options. First, since I have not see a "pre or post" script on any of my old AIX servers, the alternative would be to place your "command" entries in /usr/local/etc into a filename of your choice and then have cron execute the filename at the time you need it to run. This file could contain steps to suspend alert messages, perform a database shutdown or alteration command, or whatever pre scripts you want to perform, then perform dmsc backups, and finally perform your post scripts and then exit. Your Second option would be to create a client option set - where your Pre and Post scripts will be inserted with different sequence numbers. The final option would be, especially if this a Stand Alone script, is to place this in either an Administrative or Client Schedule, where the schedule type is obviously "command'. Between these three options, I hope that one of them will suit your needs.
Good Luck
Steven