Re: Excessive IOPS to shared ORACLE_HOME

From: Chen Shapira <>
Date: Mon, 25 Aug 2008 17:49:50 -0700
Message-ID: <>

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: 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.

Thanks again,
Chen Shapira

On Thu, Aug 21, 2008 at 10:47 PM, Vasu Balla <> 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

Received on Mon Aug 25 2008 - 19:49:50 CDT

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