WARNING:Could not set the asynch I/O limit to 64 for SQL direct I/O. It is set to 0

Problem:

I’ve got so many trace file generated every a few second that contains some of these WARNING:

WARNING:Could not set the async I/O limit to 64 for SQL direct I/O. It is set to 0
WARNING:Could not set the async I/O limit to 128 for SQL direct I/O. It is set to 0

Solution:

1. Download patch 8217795 from Oracle Metalink. And apply patch.
2. Change parameter file:
   alter system set disk_asynch_io=false scope=spfile;
3. Restart database