ORA-27090 Unable to Reserve Kernel Resources Error

I got ” ORA-27090 Unable to Reserve Kernel Resources Error ”  error in Oracle database.

 

ORA-27090 Unable to Reserve Kernel Resources Error

 

Details of error are as follows.

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

 

 

Unable to reserve kernel resources for asynchronous disk I/O

This ORA-27090 is related with the system call to reserve kernel resources for asynchronous I/O has failed.

You discover messages of this nature in your alert log:

ORA-27090: Message 27090 not found; product=RDBMS; facility=ORA

Additional information: 3
Additional information: 128
Additional information: 65536

– OR –

ORA-27090: UNABLE TO RESERVE KERNEL RESOURCES FOR ASYNCHRONOUS DISK I/O

Additional information: 3
Additional information: 128
Additional information: 65536

– OR –

ORA-27090: Message 27090 not found;  product=RDBMS; facility=ORA
Linux-x86_64 Error: 4: Interrupted system call
Additional information: 3
Additional information: 128
Additional information: 65536

Strace against DBWR shows:

io_setup(4096, 0x66e1588) = -1 EAGAIN (Resource temporarily unavailable),

which is related to “aio-max-nr” kernel limit.

 

The “aio-max-nr” kernel limit is too low.

 

The “aio-max-nr” kernel limit should be adjusted according to Oracle recommendations which are available in this document:

Also, this parameter should be set as follows:
————————————-
fs.aio-max-nr= 3145728
————————————-

Per bug Bug 13554729 – CORRECT FS.AIO-MAX-NR = 3145728

 

Do you want to learn Oracle Database for Beginners, then read the following articles.

Oracle Tutorial | Oracle Database Tutorials for Beginners ( Junior Oracle DBA )

 

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About Mehmet Salih Deveci

I am Founder of SysDBASoft IT and IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress [email protected].-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  [email protected] a mail atabilirsiniz.

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