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Asynchronous I/O [message #60315] Sun, 01 February 2004 23:56 Go to next message
Vivek Thakur
Messages: 1
Registered: February 2004
Junior Member
Hi,

The following warning messages are logged into Database whenever Oracle has encountered problems while trying to perform asynchronous I/O. This could be due to heavy I/O intensive operation, short of memory for Buffer Cache and sort operations in the database.
 
We feel that the immediate solution is to restart the database by disabling asynchronous I/O in the database.  (By setting the following parameters in the init.ora file of the database : disk_asynch_io = false, dbwr_io_slaves to any value other than Zero), until the root cause of the problem need is  identified.
This is the Warning Message that we are getting

WARNING: aiowait timed out 1 times
WARNING: aiowait timed out 2 times
WARNING: aiowait timed out 3 times
WARNING: aiowait timed out 4 times
WARNING: aiowait timed out 5 times
WARNING: aiowait timed out 6 times
WARNING: aiowait timed out 7 times
WARNING: aiowait timed out 8 times
WARNING: aiowait timed out 9 times

Can anyone help us out for the above problem

Regards

Vivek

 

 
Re: Asynchronous I/O [message #60317 is a reply to message #60315] Mon, 02 February 2004 02:38 Go to previous messageGo to next message
Frank Naude
Messages: 4580
Registered: April 1998
Senior Member
Hi,

See Metalink Note:222989.1 "Warning "aiowait timed out 1 times" in alert.log"

Possible fixes as per the above mentioned note:

1. Restart the database without asynchronous I/O
2. Reduce I/O load on the system from this and other databases
3. Check all Oracle prerequisites for O/S and I/O subsystem configuration
4. Check for known O/S issues with Asynchronous I/O operation

Best regards.

Frank
Re: Asynchronous I/O [message #61793 is a reply to message #60317] Fri, 28 May 2004 02:39 Go to previous message
Frank Naude
Messages: 4580
Registered: April 1998
Senior Member
Hi,

If you get this error on a SUN Solaris system, also look at the following SunSolve document:

Sun Alert ID: 28311

Synopsis: Persistent Write Contention for File System Files May Result in Degraded I/O Performance

Impact: File system I/O performance at the application level appears to be very slow or hung

Symptoms:
WARNING: aiowait timed out %d times
... or
ORA-27062: skgfospo: could not find pending async I/Os

Best regards.

Frank
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