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Don Burleson Blog 







ORA-27090 Unable to Reserve Kernel Resources Error Tips

Oracle Database Tips by Donald BurlesonJune 8, 2015

Question:  I am seeing this ORA-27090 message in my Linux alert log at system startup time:

ORA-27090: Message 27090 not found; product=RDBMS; facility=ORA
ORA-27090: Message 27090 not found; product=RDBMS; facility=ORA Linux-x86_64 Error: 4: Interrupted system call  

How do I fix this ORA-27090 error?

Answer:  The oerr utility show this detail for the ORA-27090 error, indicating that a ORA-27090 error is caused by an OS kernel parameter limitation causing a lack of system resources.   

ORA-27090:  Unable to reserve kernel resources for asynchronous disk I/O  

Cause:  The system call to reserve kernel resources for asynchronous I/O has failed.

Action:  Check errno  

In Linux, this error can appear when the /sbin/sysctl parameter "aio-max-nr" kernel limit is set too low.

You can cease the ORA-27090 error by increasing the "aio-max-nr" kernel limit as per the Oracle recommendation:

fs.aio-max-nr= 3145728

  MOSC note 748607.1 has complete details on the ORA-27090 error, and Oracle > claims that the ORA-27090 error will not appear in release 11.2 and beyond.

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