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Process Spins and Traces with 'Asynch I/O Kernel Limits' Warnings or IO_SUBMIT Failed Due to Kernel Limitations (Doc ID 1313555.1)

Last updated on OCTOBER 10, 2022

Applies to:

Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database - Enterprise Edition - Version 10.2.0.4 to 11.1.0.7 [Release 10.2 to 11.1]
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.

Symptoms

In 10.2.0.4 and 10.2.0.5 ,on Unix Platforms , an infinite spin can be observed when Asynch IO enabled ie: DISK_ASYNCH_IO=TRUE with the following error messages in the trace files:

WARNING:Could not increase the asynch I/O limit to 514 for SQL direct I/O. It is set to 128
WARNING:Could not increase the asynch I/O limit to 544 for SQL direct I/O. It is set to 128
WARNING:Could not increase the asynch I/O limit to 574 for SQL direct I/O. It is set to 128
WARNING:Could not increase the asynch I/O limit to 604 for SQL direct I/O. It is set to 128

 

WARNING:io_submit failed due to kernel limitations MAXAIO for process=0 pending aio=0
WARNING:asynch I/O kernel limits is set at AIO-MAX-NR=65536 AIO-NR=65464
WARNING:1 Oracle process running out of OS kernelI/O resources aiolimit=0

Cause

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