Increase Open Files Limit to resolve Too Many Open files error and native OutOfMemory due to failed to create thread

Suddenly we faced the error 'Open file limit ' while login on Linux server and try to run df -h or any other command.

The likely cause of this issue is hitting max "Open file limit". This error indicates that all available file handles for the process have been used.

To resolve this issue we need to increase the size of ulimit -Sn. The ulimit command allow you to control user resource limit is the system such as process data size , virtual memory and process file size , no of processes etc.

Current value of ulimit -Sn is 1024. Here we need to increase the value of ulimit -Sn. 

#ulimit -Sn

1024




#ulimit -a




core file size          (blocks, -c) 0

data seg size           (kbytes, -d) unlimited

scheduling priority             (-e) 0

file size               (blocks, -f) unlimited

pending signals                 (-i) 1031260

max locked memory       (kbytes, -l) 64

max memory size         (kbytes, -m) unlimited

open files                      (-n) 1024

pipe size            (512 bytes, -p) 8

POSIX message queues     (bytes, -q) 819200

real-time priority              (-r) 0

stack size              (kbytes, -s) 10240

cpu time               (seconds, -t) unlimited

max user processes              (-u) 1031260

virtual memory          (kbytes, -v) unlimited

file locks                      (-x) unlimited

Increase the limit temporary.

It can be increased temporarily for the current session by setting

#ulimit -Sn 4024

#ulimit -Hn 653223

Increase the limit permanently.

For permanently we need to edit /etc/security/limits.conf for root user or non-root user as well.

#cat /etc/security/limits.conf

####setting for nofile soft limit is 1024

oracle   soft   nofile    4024

*        soft nofile  4024

### oracle-rdbms-server-11gR2-preinstall setting for nofile hard limit is 65536

oracle   hard   nofile    65536

*   hard   nofile    65536

Once you save file, you may need to logout and login again.

Finally verify the value.

[root@***** ~]# ulimit -Sn

4096

[root@***** ~]# ulimit -Hn

65536