Re: Oracle 11.2 on AIX 7.1 JFS2 mount options

From: Martin Klier - Performing Databases GmbH <>
Date: Thu, 22 Dec 2016 11:06:40 +0100 (CET)
Message-ID: <>


thank you very much for your clarification and advice. If we get the chance to do the testing, I'll let you know.

Have a nice Christmas time!


Martin Klier | Performing Databases GmbH 
Managing Partner | Senior DB Consultant 
Oracle ACE | 

> Von: "Rich J" <>
> An:
> Gesendet: Mittwoch, 21. Dezember 2016 21:11:49
> Betreff: Re: Oracle 11.2 on AIX 7.1 JFS2 mount options

> On 2016/12/21 13:46, Martin Klier - Performing Databases GmbH wrote:
>> I am calling out for Oracle-on-AIX knowledge/experience bearers, and have a >> question whether setting the "cio" mount option for datafiles, redo logs and >> control files for DB version on AIX 7.1 with JFS2 or not. >> We are using filesystemio_options=setall for this customer setup. >> ... >> Simple question: >> I have massively concurrent IO on datafiles (usual read/write activity) and redo >> logs (streams capture) with many (so far unavoidable) "db file sequential read" >> and "log file sync" waits. >> Should I activate JFS2 mount option -cio for my data files and redo log file >> systems?
> Short answer: use "filesystemio_options=setall" in Oracle 11.2 and do not use
> the "cio" mount option on JFS2 mountpoints in AIX 7.x.
> You can verify that CIO is being used by tracing sessions on a test Oracle
> instance. A google and MOS 1478924.1 can help you with that. Please test! When
> you run into issues in the future, you can prove that it's not a lack of CIO
> that is the problem.
> Also see the "AIX Concurrent I/O for Oracle archive logs" thread on this list
> from 2010.
> "log file sync" waits do not necessarily come from slow disk resulting from
> suboptimal IO setup. I have very low latency writes, but have log file sync
> waits due to over-committing, for (a poor) example.
> GL!
> Rich
Received on Thu Dec 22 2016 - 11:06:40 CET

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