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1 oedwards commented Permalink

The latest recommendation is not to set CIO on the filesystems at all. It's now possible to have your DBA's specify in their Oracle 10/11 configurations to use CIO (via the API), so they can control the CIO from the database end. No more mounting filesystems with CIO!

2 AnthonyEnglish commented Permalink

Thanks for that. I found this document from Oracle <br /> http://download.oracle.com/docs/cd/B19306_01/server.102/b15658/appa_aix.htm <div>&nbsp;</div> which explains what you say: <br /> With Oracle Database 10g, you can enable Direct I/O and Concurrent I/O on JFS/JFS2 at the file level. You can do this by setting the FILESYSTEMIO_OPTIONS parameter in the server parameter file to setall or directIO. This enables Concurrent I/O on JFS2 and Direct I/O on JFS for all data file I/O. Because the directIO setting disables asynchronous I/O it should normally not be used. As a result of this 10g feature, you can place data files on the same JFS/JFS2 file system as the Oracle home directory and still use Direct I/O or Concurrent I/O for improved performance. As mentioned earlier, you should still place Oracle Database logs on a separate JFS2 file system for optimal performance. <div>&nbsp;</div> <div>&nbsp;</div> The following section made me stick to cio at the file system level, but it looks like I don't have to do that now: <div>&nbsp;</div> Concurrent I/O is a better setting than Direct I/O on JFS2, because it provides support for multiple concurrent readers and writers on the same file. However, due to AIX restrictions on JFS2/CIO, Concurrent I/O is intended to be used only with Oracle data files, control files, and log files. It should be applied only to file systems that are dedicated to such a purpose. <div>&nbsp;</div> <div>&nbsp;</div> <div>&nbsp;</div>