So I have mentioned before about the replication product that we use that is based on Archived Redo Logs (Golden Gate). Well sometimes the replication process abends before the RMAN backup. Since there is no communication between the two processes, RMAN happily removes archived logs that the replication process might need the next time it starts up.
Because of this we usually like to keep a few hours worth of archived logs hanging around.
Does this suck up disk space? Yes.
Is it worth it sacrifice some disk space in order to save us some DBA time? Absolutely.