Re: DISK configuration - help please.

Raid 5 is fine if you want to be real redundant and safe with mirroring and (i think) it's cheap.... But, as all Oracle people know (and database people in general) Oracle databases are I/O bound. If you use raid 5 with all it's extra disks, then Oracle and the OS will have to write to all those extra disks. Talk about a performance problem. Read any book, right now I'm reading one about performance tuning with the Oracle kernel and the Unix kernel. One of the first thing the author talks about is raid. He doesn't spend much time on it, but he specifically states the differences about them and why they are good/bad for Oracle.

HTH I don't remember the name of the book or the author at the moment. Lyall Barbour

At 11:17 AM 8/17/00 -0800, you wrote:
>I am not going to be much help in regards to your initial question, but I am
>wondering what is wrong with RAID 5? I have had alot of success with that
>configuration in the past. What am I missing?
>
>Steve McClure
>----- Original Message -----
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Sent: Thursday, August 17, 2000 11:14 AM
>
>
> > Get rid of RAID 5.
> >
> > Lyall
> >
> > At 06:46 AM 8/17/00 -0800, you wrote:
> >
> > >I am in the process of building two DB servers - one live and the other
> > >standby. We are not overly concerned with disk capacity - but rather
>with
> > >speed of access.
> > >
> > >Our current configuration is
> > >
> > >primary has 10 disks in RAID 0+1
> > >standby has 6 disks in RAID 5
> > >
> > >This is to give us 5 physical devices for production - I think a holdover
>of
> > >OFA guidelines.
> > >
> > >What I am looking for is a bit of advice on the best optin for current
> > >configurations. I can add disks to this later. I am also using Veritas
>VM
> > >and FS and so can relayout my RAID 5 to RAID 0+1 pretty easily as well.
> > >Adding disks to the system is also a breaze.
> > >
> > >All of these disks are in one FS mounted to /u01 .. .for easy management
>on
> > >our site we elected one mount point and one very expandable FS.
> > >
> > >I am considering breaking my configuration and going with 8 disks in 0+1
>for
> > >both systems - or going with 10 and 6 but both in 0+1 - I don't think
>that
> > >RAID 5 is a good idea ever - even for a standby system, but there is some
> > >pressure to have 5 physical devices and RAID 5 with 6 gives us that
>too...
> > >
> > >
> > >Anybody out there willing to throw two cents my way?
> > >
> > >
> > >thanks!
> > >
> > >adam
> > >--
> > >Author: Adam Turner
> > > INET: ATurner_at_concretemedia.com
> > >
> > >Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
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> > --
> > Author: Lyall Barbour
> > INET: lbarbour_at_stanford.edu
> >
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>
>--
>Author: Steve McClure
> INET: steve_at_pactr.com
>
>Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
>San Diego, California -- Public Internet access / Mailing Lists
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Received on Thu Aug 17 2000 - 17:36:30 CDT