Re: Oracle 11.2 on AIX 7.1 JFS2 mount options

Stefan,

especially the technical background was interesting, and the paper is a very good reference for customer discussions.

Thank you very much!

Martin

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

martin.klier_at_performing-db.com | http://www.performing-databases.com 



> Von: "Stefan Koehler" <contact_at_soocs.de>

> An: "martin klier" <martin.klier_at_performing-db.com>

> CC: "ORACLE-L" <oracle-l_at_freelists.org>

> Gesendet: Mittwoch, 21. Dezember 2016 22:27:23


> Betreff: Re: Oracle 11.2 on AIX 7.1 JFS2 mount options





> Hey Martin,

> well let's say it this way - i worked way too many years with this crappy OS


> (e.g. USLA heap, dropped or hung TCP/IP packets in stack, wrong

> getrusage(), etc.) for Oracle databases and still need to nowadays from time to

> time ;-)




> > Still open questions: Is this SAP Note's advice still valid for AIX 7.x ?





> Please forget the SAPnote and read the mentioned paper or let me quote the


> corresponding part from it: "AIX 6.1 and AIX 7.1 combined with Oracle >=

> 11.2.0.2 introduced a new open flag O_CIOR which is same as O_CIO, but this

> allows subsequent open calls without CIO. The advantage of this

> enhancement is that other applications like cp, dd, cpio can access database

> files in read only mode without having to open them with CIO. Starting

> with Oracle 11.2.0.2 when AIX 6.1 or AIX 7.1 is detected, Oracle will use O_CIOR

> option to open a file on JFS2. Therefore you should no longer mount

> the filesystems with mount option –o cio."


>> My big question is if O_CIOR really does the same per file as O_CIO does for the


> > file system.





> I_CIO is a flag that is set as a parameter by calling fopen() and in the old


> days (before O_CIOR) this caused issues if your database has opened the

> files with the I_CIO flag (due to filesystemio_options=setall) and you did not

> mount the filesystem with the "cio" option. In consequence third party

> tools (like cp or mostly flat file copy / backup tools) tried to open these

> files without the I_CIO flag and failed. This "mixed" fopen() mode works

> nowadays with the flag O_CIOR - so no need for mount option "cio" anymore. You

> also can truss it :-)




> Best Regards


> Stefan Koehler





> Freelance Oracle performance consultant and researcher


> Homepage: http://www.soocs.de

> Twitter: _at_OracleSK


>> Martin Klier - Performing Databases GmbH <martin.klier_at_performing-db.com> hat am


> > 21. Dezember 2016 um 21:29 geschrieben:





> > Stefan, sometimes you are frightening me. :)


> > Thanks, will look that paper up.




> > Still open questions: Is this SAP Note's advice still valid for AIX 7.x ?


>> My big question is if O_CIOR really does the same per file as O_CIO does for the


> > file system. The SAP note seems to tell otherwise.



>> But if I am not allowed to set CIO any more, how can I get concurrent WRITE


> > capability?






> > --

> > Martin Klier | Performing Databases GmbH


> > Managing Partner | Senior DB Consultant

> > Oracle ACE




> > martin.klier_at_performing-db.com | http://www.performing-databases.com


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