RE: Migrate from AIX to Linux
Date: Fri, 18 Dec 2015 02:36:05 -0800
Message-ID: <03f401d1397f$eb5a0470$c20e0d50$_at_comcast.net>
I must apologize for the brevity of my previous answer causing your misunderstanding of my recommendation. Let me rephrase.
I believe we as DBA/DBE should stop worrying about CIO/DIO and the choices different components of Oracle will make in the background and move off of file systems into ASM whether you are on Linux or AIX.
We were able to achieve much better performance and resource utilization on AIX with ASM than with JFS2 with CIO while I worked at Costco on OLTP and DW systems. (Both from a benchmark and real world system usage perspective.)
Also, if you are already utilizing ASM in other parts of your environment then it makes your whole system homogenous by converting the *NIX’s too.
Matthew Parker
Chief Technologist
425-891-7934 (cell)
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From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Rich J
Sent: Thursday, December 17, 2015 1:51 PM
To: oracle-l_at_freelists.org
Subject: RE: Migrate from AIX to Linux
On 2015/12/17 15:00, Dimensional DBA wrote:
CIO is redundant to Oracle overall I/O and caching mechanisms. You should use Oracle ASM on Linux.
OK, you've got me curious now. With Oracle 10g+ on AIX, where filesystemio_options=setall and the database files are on JFS2, DBWR will implicitly use CIO, even if CIO isn't specified on the mountpoint. CIO should not be used anywhere else for the database (e.g. not on redo logs or binaries), per Oracle and IBM.
Are you saying that one should purposely not use CIO on AIX? It seems like that would incur performance penalties for the DBWR, including dbfile creation/extension and restores.
Rich
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Dec 18 2015 - 11:36:05 CET