Re: Excessive IOPS to shared ORACLE_HOME
Date: Mon, 25 Aug 2008 17:49:50 -0700
Thanks Vasu and Riyaj,
I see Pythian is employing most of the RAC experts ;)
Allowing attribute cache on Oracle Home mount indeed solve the problem! Thank you so much!
However, this Netapp document: http://www.netapp.com/library/tr/3536.pdf recommends mounting Oracle Home with "actimeo=0". So I'm reluctant to go against these recommendations. Maybe they are based or experience or bugs... (I admit there is a good probability that they are based on copy-paste as well).
I opened an SR with Oracle and with Netapp, asking for clarification on these issues, and I'll update when there are news.
On Thu, Aug 21, 2008 at 10:47 PM, Vasu Balla <appsdba_at_gmail.com> wrote:
> Oracle on netapp rings some bells for me. Oracle recommends using noac or
> actime=o options when mounting nfs for Datafiles, Voting Disk and OCR. Noac
> means "no attribute cache" means none of the file attributes are cached in
> the filesystem cache, which is very much needed for RAC. If you put your
> shared oracle home also in that mountpoint which is mounted noac, every
> access to a file in the oracle home requires a physical IO at the netapp. So
> I recommend moving all software directories ( db oracle home, asm oracle
> home and crs oracle home etc ) to a nfs mount which is not mounted with noac
> or actime=o. This will reduce your excessive IO per sec issue