Re: Oracle Disk Configuration question.

bc9am <bc9am_at_hotmail.com> wrote in message news:<ph7vc.248$Xh3.65_at_newsfe1-gui.server.ntli.net>...
> Hi,
>
> I'm trying to understand what the best disk configuration is for an
> Oracle server I am trying to build. Currently the server is spec'ed to
> have 4 disks. In my mind that gives me two choices. Either two sets of
> RAID 1, or a big RAID 5 array. It's a high availability server so I
> can't afford downtime due to a dead disk.
>
> After a bit of research I have understood that you are supposed to put
> all your core database (table?) files (and any random access stuff [inc
> OS files?]) on one disk, and sequential stuff on their own disks (e.g.
> logs). I obviously don't have enough disks to put all sequential files
> on their own disks. So, with this in mind I guess logic suggests putting
> them all on one disk. However this seems a bit silly as then its just
> random access (?) - so I might as well have a RAID 5 array for the whole
> lot?
>
> Obviously with this particular configuration cost is an issue, so
> performance isn't the number one priority.
>
> Can anyone comment on any of the above or point me in the right
> direction of a good resource talking about the options available (I seem
> to just come across resources that are either just wrong, or only say
> the 100% right way to do it with no flexibility for cost saving - I
> can't afford a 10+ physical disk solution).
>
> Are there any generic examples of how to partition for Oracle in a Linux
> environment?
>
> Thanks.

The disadvantages of using RAID-5 for online redolog files and controlfiles have been explained here many, many, many, many times. RAID-5 has a write penalty associated to it by design. If you want to read about this just visit http://www.baarf.com and you'll have some recognised Oracle specialists explain why you should NOT use RAID-5.
You may also want to read up on the SAME methodology. (SAME is an acronym for Stripe And Mirror Everything)

Sybrand Bakker
Senior Oracle DBA Received on Wed Jun 02 2004 - 04:23:07 CDT