Re: Oracle9i - which RAID ??

First of all: I worked at Oracle Norway for a couple of years. When I was working there I attended some internal courses which was beeing held by the top guys in Oracle (Core developers and others). Before I attended these courses I strongly believed in using single-mirrored disksets. My reasoning for this, was full control of the datastream. But after some long discussions with some pretty intelligent guys at developement, I did see the benefits in striping to. That is striping the mirrors, not mirroring the stripes. In RAID 5 you don't have ANY control of the datastream. It's just a black box for storing data. With RAID 0+1 you can make many stripes of small mirrored devices, which is quite a performance enhancer. And by the way : Stay clear of the mastodont discdrives. They offer a lot of storage, and little $ pr Byte, but they kill database performance.

My advice : Get the smallest discs you can get you hands on. Mirror them two by two. Stripe the mirrors.

If you'r feeling bold : Get the smallest discs you can get your hands on. Mirror two-by-two, and stripe from within the database. This CAN get you the best performance, but should only be done if you're very sure of the access-paths of your SQL's.

On Thu, 27 Jun 2002 18:21:55 +0200, Ed Stevens wrote:

 <snip>
>
> I understand the reasoning for 0+1, and I understand (some) of the
> reluctance by some to avoid RAID-5 in some areas, but don't understand
> a blanket condemnation of R5 as "humbug." Could you explain? -- Ed
> Stevens
> (Opinions expressed do not necessarily represent those of my employer.)
Received on Mon Jul 01 2002 - 00:53:14 CDT