Re: RAC/how should i store oracle files on a SAN

Moe wrote:
> Hi Everyone
>
> I'm setting up a RAC using oracle 10g on a two redhat linux 3.0
> enterprise boxes and the oracle files are going to be on the SAN (data
> files, redo logs, etc...)
> 1- My SAN is set as RAID 5 and RAID 10. so linux sees it as /dev/sda
> (raid 5) and /dev/sdb (raid 10)
> 2- I'm going to have the voting disk and registry files of the CRS on
> an OCFS partition which im going to create on the raid 5. Not sure that
> this is the best way.
> 3- Regarding the rest of the oracle files (data files, etc..
> ORACLE provides these options for cluster storage:
> raw devices
> ASM
> ORACLE cluster file system.
> I would like to know what is recommended to use.
> -Since my SAN already has a RAID, what would happen if i use ASM, is
> it a bad idea?. it's like a raid built on a raid. is there a
> performance drawback doing that?
> -Is it suggested to use OCFS for eveything?. I know it is the easiest
> to use, is their a performance issues using it even for the data files,
> redo, etc..?.
> -Is OCFS a file system that can be used on any drive, SAN?
> -I'm trying to avoid using RAW devices since it hard to manage them
> plus i need to create a partition for every file.
> -In cluster storage can i have my oracle files on other file systems
> like linux ext3 file system?
> -I'm trying to reach a decision on what file system to have my oracle
> files on based on fact that i have a SAN setup as RAID 5 and RAID 10.
>
> Thanks
>
> Moe

Forget OCFS. Oracle is in the process of forgetting it so it is not a good direction to go for a new installation. Unless your SAN is from Apple RAID5 is also like a bad idea due to the heavy penalty of writes and degradation during rebuild.

I'd strongly urge you to look at RAW managed by ASM and let ASM provide the mirroring.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)