Oracle process running out of OS kernel I/O resources

[Former Member]

Hi All,

Here is our platform:

Oracle Version: 10.2.0.4.0

O/S: Linux x86_64

We are getting the below Error Msg:

ERROR:

===================================================================

WARNING:io_submit failed due to kernel limitations MAXAIO for process=128 pending aio=123 WARNING:asynch I/O kernel limits is set at AIO-MAX-NR=1048576 AIO-NR=64384 WARNING:Oracle process running out of OS kernel I/O resources

===================================================================

To avoid this we recently upgrade the Oracle to 10.2.0.4.0 and applied the below Ipatches also but still we are getting the same error:

p6051177_10204_Linux-x8664.zip

p6024730_10204_Linux-x8664.zip

p5935935_10204_Linux-x8664.zip

p5923486_10204_Linux-x8664.zip

p5895190_10204_Linux-x8664.zip

p5880921_10204_Linux-x8664.zip

p5756769_10204_Linux-x8664.zip

p5747462_10204_Linux-x8664.zip

p5561212_10204_Linux-x8664.zip

p6944036_10204_Linux-x8664.zip

p6826661_10204_Linux-x8664.zip

p6775231_10204_Linux-x8664.zip

p6768114_10204_Linux-x8664.zip

p6679303_10204_Linux-x8664.zip

p6645719_10204_Linux-x8664.zip

p6452766_10204_Linux-x8664.zip

p6379441_10204_Linux-x8664.zip

p6324944_10204_Linux-x8664.zip

p6313035_10204_Linux-x8664.zip

p6151380_10204_Linux-x8664.zip

p6084232_10204_Linux-x8664.zip

p6082832_10204_Linux-x8664.zip

p7573151_10204_Linux-x8664.zip

p7522909_10204_Linux-x8664.zip

p7513673_10204_Linux-x8664.zip

p7300608_10204_Linux-x8664.zip

p7287289_10204_Linux-x8664.zip

p7149863_10204_Linux-x8664.zip

p7027551_10204_Linux-x8664.zip

p6972843_10204_Linux-x8664.zip

p6954829_10204_Linux-x8664.zip

p7592168_10204_Linux-x8664.zip

p8201796_10204_Linux-x8664.zip

p7592346_10204_Linux-x8664.zip

p6705635_10204_Generic.zip

p7252962_10204_Generic.zip

Do we need to set any Oracle parameters?

Thanks And Regards:

Giridhar N

[Former Member]

Hello Gridihar

refer to Note 1240150,This should help you solve your issue

"For Oracle 10.2.0.2 you can use as workaround

alter system set "_aiowait_timeouts" = 200 scope = spfile;

or

set the parameter "_aiowait_timeouts = 200" into the init<SID>.ora

In any case you need to bounce the database in order that the parameter takes effect.

With Oracle 10.2.0.4 the parameter aiowaittimeouts = 100 is already implemented. Should the warnings still occur you can use the same workaround as for Oracle 10.2.0."

Rohit

[Former Member]

Hi,

We already set that parameter " aiowaittimeouts" to 200, but still we are getting the same error.

is there any other solution for this?

Regards

Giridhar N.

[Former Member]

Hello Giridhar,

Refer to

I would suggest you to search on metalink,you will found the solution

Rohit

[Former Member]

Giridhar

SAP Note 1048686

Oracle Metalink note 27300

[Former Member]

Hello,

you may have to adjust Linux kernel parameters.

What kind of Linux is it? (RedHat, SuSE, ..?)

[Former Member]

Our Linux flavour is SUSE.

[Former Member]

Did you set Linux kernel parameters according to SAP note 1275776?

Did you install sapinit package as described there?

And by the way, note 1048686, as suggested by Bhudev, is about the operating system AIX. That's yet another flavour of Unix, it is not related to Linux.

regards

Edited by: Joe Bo. on May 5, 2009 11:40 AM

[Former Member]

note could be utilized atleast get a hint for the right direction to analyze the problem, like to check process limits for specific users like orasid, but with the help of OS team, as we also did face the same problem sometime back

[Former Member]

Thank you so much for your quick reply.

I will follow the note 1275776, and get back to you if I have any issues.

Thanks:

Giridhar N.

[Former Member]

you can check /tmp/security/limits.conf file once to see if any limit is defined for orasid user for parameter nproc. I think, nproc in Linux is same as maxuproc in Aix

[Former Member]

Hi Bhudev,

I am not finding the "/tmp/security/limits.conf file " can you please help me in finding this..

[Former Member]

it was my typing mistake

/etc/security/limits.conf

[Former Member]

Hi,

under the limits.conf i am seeing the below values:

1. Added for SAP on 2008-07-17 15:25:47 UTC

@sapsys soft nofile 48000

@sapsys hard nofile 48000

@sdba soft nofile 32800

@sdba hard nofile 32800

@dba soft nofile 32800

@dba hard nofile 32800

still i am getting the same error:

WARNING:io_submit failed due to kernel limitations MAXAIO for process=128 pending aio=127 WARNING:asynch I/O kernel limits is set at AIO-MAX-NR=65536 AIO-NR=65536 WARNING:Oracle process running out of OS kernel I/O resources (1)