Steve,

Not a consultant but . . .

I started with a RAID-1 plus RAID-5 just like your config. Quest's "Spotlight on Oracle" showed waits on the log files but (normally) nothing much else. I concluded it was due to having the pagefile on the same drive as the logs

I bought some consulting time from Oracle and we came up with the following:

- get the log & ctl files to their own disk (RAID-1) - every bit of doc I have read says this. Now you have make sure that the remaining 18Gb minus 80Mb is not used for anything else (at least during working hours)! I use it for "archive" material (NO, not archive logs!) and I backup my test system there over-night.

- the more logical disks the better, so get as many RAID-1 pairs as you can afford (until you have one db file per disk - the money usually runs out first).


The compromise I came to was 8 physical disks (4x2) instead of 5 (1x2 plus 1x3) - the question is, can you sell that?
YES, data & index are separate. A single query with full table scans does not slow down OLTP - two at the same time does, but it's acceptable.
(For completeness:
Dual processor
Disk1: OS, pagefile & "file server"
Disk2: Data & RBS
Disk3: Index, System, Temp & ArchLogs
Disk4: Logs & Ctls ONLY)
I'm sure there are arguments for different configs - I'm happy with this.