Re: Best RAID configuration.

Tony Longhurst wrote:
>
> We have a large Oracle 7.3 based database, running under NT 4, that has a
> requirement for approximately 50 GB worth of system files and dynamically
> changing tablespaces on one logical drive and upto 300 GB of read only
> tablespaces that are contained on a separate logical drive.
>
> I am considering a RAID of 0 + 1 for the system files and dynamically
> changing table spaces and RAID 5 for the static tablespaces.
>
> This would result in 6 x 18 GB drives for RAID 0 + 1 and 7 x 50 GB drives
> for RAID 5.
>
> My question is whether have just 3 drives for the striping, prior to
> mirroring, is enough. Would it be much better to have 14 x 50 GB RAID 0 + 1,
> for example, although this would be a lot more expensive. Another option
> would be to use 10 x 18 GB drives although we do not strictly need the
> capacity, would this increase the performance. This system has a heavy
> usage.
>
> Any advice gratefully received.
>
> Tony

I've always found that pretty much any system that choose disks based on the SIZE of the database end up suffering...Plan around the config that will perform and scale well - no matter how much "free" space you end up with...IMHO this typically means at the barest possible minimum

• a disk per redo log (2 if mirrored)
• archives separate
• 0+1 stripes for tspaces

and then for medium sized db's, start looking at

• temp tspaces on separate stripes
• one rollback segment per disk

and I forgot...a big chequebook.

HTH

-- 
===========================================
Connor McDonald
http://www.oracledba.co.uk

We are born naked, wet and hungry...then things get worse