Database Redundancy SET is essential set of recovery-related files. As a DBA, you need to be well prepared for any kind of contingency situation.

It should contain below:

• Recent backups of all datafiles & control file (duplex or triplex the control file at database level)
• All ARCHIVED redo logs made after the last backup
• Current control files and online redo file copies (duplex online redo files at database level)
• Oracle database-related configuration file copies (spfile, password file, tnsnames.ora and listener.ora files etc)

Operating system mirroring is good, but you should do database level mirroring wherever possible.

If you using ASM, TRY to have atleast Normal redundancy.

When setting up production systems, use at least two disk drives(one for the redundancy set and the other for the datafiles). They should be completely separated by using different volumes, file systems, disk controllers, and RAID devices to hold the two sets of files

You can set up FRA for keeping the redundancy set. Oracle RECOMMENDS the flash recovery area as a logical candidate to keep a copy of all the files belonging to the redundancy set (which includes the most recent database backup) on disk.

Database Redundancy Set is essential set of recovery-related files. As a DBA, you need to be well prepared for any kind of contingency situation.

It should contain below:

Operating system mirroring is good, but you should do database level mirroring wherever possible.

If you using ASM, try to have atleast Normal redundancy.

When setting up production systems, use at least two disk drives(one for the redundancy set and the other for the datafiles). They should be completely separated by using different volumes, file systems, disk controllers, and RAID devices to hold the two sets of files

You can set up FRA for keeping the redundancy set. Oracle recommends the flash recovery area as a logical candidate to keep a copy of all the files belonging to the redundancy set (which includes the most recent database backup) on disk.