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@xxxxxxxxxxxxxxxxx | http://www.performing-databases.com ;
Von: "Stefan Koehler" <contact@xxxxxxxx>
An: "martin klier" <martin.klier@xxxxxxxxxxxxxxxxx>
CC: "ORACLE-L" <oracle-l@xxxxxxxxxxxxx>
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: @OracleSK
Martin Klier - Performing Databases GmbH <martin.klier@xxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxx | http://www.performing-databases.com
