Database Software

Hello all,
I've successfully installed clusterware, and ASM on a 5 node system. I'm trying to use asmca (11Gr2 on RHEL5)....to configure the disk groups.

I have a SAN, which actually was previously used for a 10G ASM RAC setup...so, reusing the candidate volumes that ASM has found.

I had noticed on the previous incarnation....that several disk groups had been created, for example:

ASMCMD> ls
DATADG/
INDEXDG/
LOGDG1/
LOGDG2/
LOGDG3/
LOGDG4/
RECOVERYDG/

Now....this is all on a SAN....which basically has two pools of drives set up each in a RAID5 configuration. Pool 1 contains ASM volumes named ASM1 - ASM32. Each of these logical volumes is about 65 GB.

Pool #2...has ASM33 - ASM48 volumes....each of which is about 16GB in size.

I used ASM33 from pool#2...by itself to contain my cluster voting disk and OCR.

My question is....with this type setup...would doing so many disk groups as listed above really do any good for performance? I was thinking with all of this on a SAN, which logical volumes on top of a couple sets of RAID5 disks...the divisions on the disk group level with external redundancy would do anything?

I was thinking of starting with about half of the ASM1-ASM31 'disks'...to create one large DATADG disk group, which would house all of the database instances data, indexes....etc. I'd keep the remaining large candidate disks as needed for later growth.

I was going to start with the pool of the smaller disks (except the 1 already dedicated to cluster needs) to basically serve as a decently sized RECOVERYDG...to house logs, flashback area...etc. It appears this pool is separate from pool #1...so, possibly some speed benefits there.

But really...is there any need to separate the diskgroups, based on a SAN with two pools of RAID5 logical volumes?

If so, can someone give me some ideas why...links on this info...etc.

Thank you in advance,

cayenne