Re: raid 0+1 verses separating disk io

In article <7ul4go$k02$1_at_nnrp1.deja.com>,   raff32_at_my-deja.com wrote:
> This is a question about raid and which configuration is best for
> performances on sunOS 5.6.
> I have six nine gig drives available for an oracle database and two
> oracle dba's who differ on how to achieve the best performance.
>
> dba 1: says to put all 6 disks together in a raid 0+1 configuration
and
> end up with 27 gigs available in one directory mounted at ORACLE_BASE.
> He claims the striping of the disks will give faster access data and
> outperform separating indexes and data on different disks.
> (If this was true, this is the ideal scenario).
>
> dba 2: says to separate oracle executables, data, indexes and backup
all
> on seperate disks. This seems like it is an out of date solution
> that will waste space. The only reason I would adopt this scenario
> is if the performance was actually better than the raid 0+1
> configuration.
>
> If anyone could provide some insight into this or perhaps point me
> to a website where such a study has been documented I would be
> very appreciative.
> Thanks a lot.
>
> Steve
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

As I understand, in both the cases you are going for disk mirrorinig. (RAID 1) That's a good protection against failure. Now the question is whether to use Striping (so called Raid 0) or not.

This solely depends on nature of your database and application. If it does lots of reads and full table scans, I would recommend to go for solution 1. I do not see any great benefit of striping in transaction based env. In such cases one has to be very careful before deciding on this as it may hamper performance at times. ( I know at least one site where performance has actually degraded !)

Good luck.

-Bipin.

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Wed Oct 20 1999 - 14:49:04 CDT