Re: OLTP and RAID 5

From: Paul Brewer <paul_at_paul.brewers.org.uk>
Date: Sun, 22 Sep 2002 18:57:08 +0100
Message-ID: <3d8e2c8f_2@mk-nntp-1.news.uk.worldonline.com>

"Andrew Mobbs" <andrewm_at_chiark.greenend.org.uk> wrote in message news:yul*Q-Gyp_at_news.chiark.greenend.org.uk...
> Ora <ora_geek_at_yahoo.com> wrote:
> >I have inherited an Oracle 8i OLTP Database on Compaq / NT server ,
> >with 6 Disks of 18.5 GB Each , which has RAID 5 implemented at the
> >Hardware Level.
> >
> >All my logfiles , control files and Datafiles are all seemingly in one
> >location .
> >
> >With RAID 5 , is it true that I need not distribute the files on
> >various disk to reduce IO contention - as the files are already
> >striped on all the disks.
>
> Yes. ish.
>
> If you're seeing redo bottlenecks, it may help to move the data to
> seperate disks. Having all your control files in the one RAID-5 volume
> is somewhat high risk too.
>
> >My basic doubt is can an OLTP system and RAID 5 a good combination.
>
> There's no inherent reason why not. RAID-5 _does_ have a performance
> penalty on writes, but if its not the major system bottleneck, why worry?
> Tune real problems, not theories and dogma.
>
> --
> Andrew Mobbs - http://www.chiark.greenend.org.uk/~andrewm/

Well said.

Paul Received on Sun Sep 22 2002 - 12:57:08 CDT