REDO Logs - 3rd mirror?

UPS maintenance caused power to flicker off and on several times to our main Oracle production server causing the loss of 5 disk drives in 1 RAID array - 4 of which were used to hold just the REDO logs for 2 of 3 databases. These 2 Oracle databases were setup to multiplex on 2 RAID1 (mirrored) disks. This is a large Unix server, SunFire V880 8CPUs with 4 RAID A1000s (total disks about 54) and running Oracle8i 8.1.7.3 and 8.1.7.4 . The 3rd database is on totally separate RAID arrays with its own Oracle Home software and hardly missed a beat - 15 minutes to reboot.

Anyway, I recovered from the previous night hot backup and recovered using the archived logs that were generated since the hot backup. But, we did lose some data, 1 hour for 1 database and about 2.5 hours for the other database.

Trying to prevent this, I am thinking of either shortening the potential window of lost data (REDOs) (is this possible even - depends on activity right?) or mirroring Oracle to a 3rd location (cross mirroring between the 2 main databases which are on totally separate RAID systems - but concerned about contention).

Does anyone else even use a 3rd multiplex REDO member ? I haven't , but will probably do this especially considering the current 2 RAID1 mirrors are in 1 array.

Next time we get new hardware I will make sure the Sys Admins know the 2 mirrors I usually ask for should be on separate RAID arrays. I should have caught that. The 3rd database DOES have its 2 RAID1 mirrors in separate arrays. Losing data bothers me, although these clients were not too upset. We have other clients who would probably be less forgiving. Received on Tue Jan 21 2003 - 23:19:16 CST