Re: RAID experience/recommendations

CLOSEP1_at_westat.com wrote:
>
> Thanks for any and all input anyone may have.
>
> We have Oracle v7.3x Enterprise Server running on our HP9000 server.
> We are in the process of reviewing mirroring and RAID options that we
> wish to implement early next year.
> I vaguely remember Oracle recommendations against RAID 5 and in favor of
> RAID 0+1, although I couldn't dig up any specific info.
> We are looking at both hardware and software mirroring and RAID options.
> Does Oracle have any white paper re: using RAID with Oracle databases?
>
> Thanks in advance for all replies.
>
> - Paul Close (Westat)

Hi Paul:

At work, I'm using DEC Alpha 2100/250 servers with 512MB memory, DEC HSZ40 Raid controllers with 32MB cache and about 128GB disk online for multiple 12GB PeopleSoft databases. Originally I had set up the drives for RAID5, but found the sustained write rate of <2MB/sec unbearable; the sustained read rate of 7MB/sec was ok. Had to change to RAID0+1 to get performance I needed, not only for our production system, but also to refresh a read-only reporting database nightly from production in a reasonable amount of time. Of course you use a lot more disk for RAID0+1 (striped mirrors) than RAID5, but disk is getting really cheap. Just our RAID controllers and enclosures seem to stay pricey.

I'm now using RAID5 only for relatively static history tables that are refreshed/updated infrequently.

Hope this helps.

-- 
Barry P. Grove                          BarrySoft Systems Applications
grovebg_at_iSTAR.ca                        (604)929-5433
Developer, Oracle DBA, Unix Sysadmin    North Vancouver, BC, V7H-2G4