JFS2 options for Oracle database

JFS2 Filesystem is pretty much the filesystem on choice for an Oracle database running on AIX. The question that always comes up is, what filesystems options should I use when using it for an Oracle database.

Here is what Oracle recommend:

Oracle database file	JFS2 Filesystem options
Control Files	cio
Data Files	cio
Log Files	cio, agblksize=512
ORACLE_HOME	cio option not supported

How to create a file system for the Oracle logs with agblksize=512
# mkfs -s <fs_size> -o agblksize=512 /ora_log

# mount /ora_log

How do you update an existing jfs2 filesystem to have the cio option:
chfs -a options=cio /ora_data   

With Oracle 11g we can enable dio and cio on jfs2 at file level. This is done by setting the FILESYSTEMIO_OPTIONS parameter in the server parameter file to setall or directIO. This enables Concurrent Input-Output on JFS2.

SQL> ALTER SYSTEM SET FILESYSTEMIO_OPTIONS=SETALL SCOPE=SPFILE; System altered. SQL> SHOW PARAMETER FILESYSTEMIO_OPTIONS NAME                                 TYPE        VALUE ------------------------------------ ----------- ------------------------------ filesystemio_options                 string    SETALL

setall enables both direct/IO and asynchronous I/O wherever possible.

Oracle Database logs files should be on a separate JFS2 file system for optimal performance.

Here are some good links talk about jfs2 and Oracle:
http://docs.oracle.com/cd/E11882_01/server.112/e10839/appa_aix.htm
http://haveyoutriedtoswitchitonandoff.blogspot.com/2009/08/tuning-jfs2-for-oracle.html