The scenario is that RMAN archivelog backups are scheduled to tape (TSM) every 2 hours. The scheduling ensures that such backups are run in a mutually exclusive fashion. A separate crontab based mechanism has been put in place (by an unrelated team) with the result that "identical" RMAN archivelog backups are sometimes run at the same time.
Are there any potential problems with this, as regards to subsequent restore operations?
Normally RMAN takes care of this. It will only make a backup of the archivelog files of which it does not have a backup.
The restore just reads the archivelogs that it needs from tape.
How about the archive log deletion being configured? When we running concurrent archivelog backup jobs, we should make sure that deletion is also configured properly to maintain the integrity in backup target.
No, there will be no problem when you restore. I does not matter which jobb backed up the archive.
If RMAN starts an archive backups it first creates a list of archive that have to be backed up: this are the archives created by the database until now that weren't already backed up. Then the job starts to backup the archive logs. if your job wants to backup an archive from its list but don't find it anymore because in the meantime it was backed up and deleted by a concurrent running job you will get an error message that your job is missing an archive and cannot backup it.
