My client currently uses O/S file level backups to backup their Oracle databases, in conjunction with an EMC BCV (another disc mirror which is split off).
During normal operation, all parts of the database are written to 3 mirrors. When it's backup time, the tablespaces are put in backup mode (or sometimes they even shutdown the db) ; then the 3rd mirror - the backup BCV - is split, so it no longer gets written to. Then, tablespaces are taken out of backup mode (or db restarted). The backup is then taken from the BCV, without any I/O on the actual (active) database devices.
We're going to implement RMAN. I was wondering if there's anything in RMAN to make use of this 3rd mirror / BCV, or if we just ditch it and backup in the usual way.
They're just afraid of the impact on their night batches of backing up from the live database devices.
Would appreciate your thoughts and comments on this.