RAID and Oracle Databases

We are currently getting ready to configure a new HP9000 K460 Server. We have
purchases a 20 disk array w/ two controllers.

We have a few older HP boxes that were configured with RAID5 disk arrays and all
Oracle datafiles, redo logs, etc. have been stored on the disk array.

I am very hesitant about configuring this new box with on line and archived redo logs
and temporary tablespace on RAID 5. I understand that redo logs should not be put on
disk arrays if possible, but that is my only option. Therefore, my configuration plan is as
follows:

1. Bind 9 disks as a RAID5 Logical Unit and assign to one controller. I plan on putting my true datafiles and indexes on this unit.
2. Bind 10 disks as a RAID 1 (or 1/0) Logical Unit and assign to the other controller. I am planning on putting on line-redo logs, archived redo-logs and the temporary tablespace on this unit.
3. Have the remaining disk as a hot-swappable.

My question regarding this configuration is: even though I am able to keep redo logs off
RAID 5, am I going to gain an even bigger performance problem with controller
contention? Which is worse, Redo's, etc. on RAID 5 - or - some controller contention?
As far as I have researched, it is my understanding you can only have 1 logical unit per
controller - is this correct?

Any advice you can send my way is VERY much appreciated. Please respond to all. Received on Tue Oct 20 1998 - 00:00:00 CDT