RE: RAID help

On Fri, 26 May 2000, George.Brennan_at_warnermusic.com wrote:
> Hmmmm.
>
> > I got a problem. I was asked to tune the database as its performance
> > very poor. Here is the existing database layout.
> >
> > Machine : IBM Netfinity 5500 M-20 with 2 x 550MHz processors.
> > disks : RAID5 disk array with 4 x 9.1 gigs (net 27 gigs)
> > with additional scsi channel connected to DLT tape drive external
> > OS : WinNT 4.0 service pack 6
> > Oracle : 8i standard edition with one 8k block instance
> > Application: web application through Story server
> > The entire disk array is made into 2 logical drives. 5 gigs and 22
> > gig OS and Oracle is installed on small logical drive and Data , index,
> > RBS, TEMP, LOB tablespaces ,exports, REDOs and Archive logs are on 22 gigs
> > logical volume.
> >
> > I advised the client to replace RAID5 with RAID0 + 1.
> > Unfortunately Hardware does not support. IBM guy clarified this.
> >
> Clarifed? RAID 0+1 is striping an mirroring
>
> > The client does not want to spend any amount for additional disks.
> > I left with two options :
> > 1. To go for IBM enhanced RAID1 (striping + mirror)
> > 2. Live with RAID5
> > In the above cases, Please suggest me for suitable database layout
> > which will
> > give improve present bottleneck of disk I/0 .
> > Before tuning RDBMS and SQL, I would like to come to baseline
> > compromise with database layout.
> >
> You have 4 x 9 gig disks.
> The client doesn't want to spend any more.
>
> Only one answer really.
>
> Scrap the RAID and use 4 individual drives and implemment a proper backup strategy.
>
> C: NT/Oracle * logs
> D: data
> E: Index
> F: temp/redo
>
> RAID and ORACLE with 4 drives is a waste of time.
>

And you could mix index and data (that are accessed serial) and put D: and E: together with raid 0.

oli.

Oliver Artelt                                     Jordanstr.7, 39112 Magdeburg
mailto:oli_at_cubeoffice.de                    Tel: 0391-6112820 Fax: 0391-604243 
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