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Don't mix Direct I/O with Concurrent I/O on oracle datafiles FS

This is and important oracle note to take in account when using CIO, posted in the itrc, it says you shouldn't use them together, I haven't been able to test this out performance wise, if someone has, please comment on the result of your tests, because oracle doesn't always get it right with HP-UX and mount point options...

Oracle Support Doc ID ID 1231869.1

Do not use "-o cio" and "-o mincache=direct,convosync=direct" together. Use either Direct I/O or Concurrent I/O.

Using Direct I/O and Concurrent I/O("-o mincache=direct,convosync=direct,cio") may cause performance regression.

Placing Oracle binaries ($ORACLE_BASE directory) on a filesystem mounted with "cio" may cause data loss and other unexpected problems.

And Finally:
Concurrent IO is not expected to provide a performance benefit over direct IO when used with online and archived redo logs.

- use none of cio,mincahce=direct,convosync=direct on Oracle binares
- use cio on datafiles
- use mincahce=direct,convosync=direct on online/archive redo logs

Unix Systems: 

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