Re: RAID Suggestions

From: Just Visiting <guest_at_example.com>
Date: Tue, 15 Jun 1999 00:00:17 GMT
Message-ID: <lIg93.34585$tm6.22046@news.rdc1.sdca.home.com>

RAID-5 has some performance trade-off issues. The perfomance of RAID-5 degrades as the ratio of writes to reads increases. The reason why this is true is because when a data block that is written to a RAID-5
volume, the XOR data block for that "cylinder" also need to be be updated. This results is a corresponding additional write operation for the XOR data.

So when you have many read operation relative to the number of data write operations, there is minimal overhead from the RAID-5 volume. It would be a BAD idea to place the archive logfiles on a RAID-5 volume.

HTH & YMMV!

---

<rspeaker_at_my-deja.com> wrote in message news:7k3bas$t8q$1_at_nnrp1.deja.com...
> Hi,
>
> I am looking for some basic suggestions / advice for setting up Oracle
> on an AIX RS/6000 using RAID. My initial plan included full disk
> mirroring at the OS level, but I'd like to move that to a RAID
> configuration and gain more usable disk space if possible.
>
> I have heard tales that RAID 5 is bad for Oracle ... is this true?
>
> Are there certain things that should or should not be included in the
> RAID arrays?
>
> Thanks for the advice....
>
> -Roy
>
>
> Sent via Deja.com http://www.deja.com/
> Share what you know. Learn what you don't.
Received on Mon Jun 14 1999 - 19:00:17 CDT