Re: Oracle 11.2 on AIX 7.1 JFS2 mount options
- From: Rich J <rjoralist3@xxxxxxxxxxxxxxxxxxxxx>
- To: oracle-l@xxxxxxxxxxxxx
- Date: Wed, 21 Dec 2016 14:11:49 -0600
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 11.2.0.4 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
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