Check the actual ulimits for all the running Oracle instances

I’ve read the recent good post from my friend Rene on Pythian’s Blog about how to troubleshoot when user ulimits are different from what specified in limits.conf:

Quick Tip : Oracle User Ulimit Doesn’t Reflect Value on /etc/security/limits.conf

I would like to add my 2 cents:

Once you fix the problem, you may want to check (any maybe monitor) when an instance is running with a wrong value (and maybe encounter the famous Error message: Linux-x86_64 Error: 23: Too many open files in system).

for pmonspid in `ps -eaf | grep [p]mon | awk '{print $2}'` ; do ps -f -p $pmonspid  ; grep "open files" /proc/$pmonspid/limits ; done

This single line gives you an overview of all your instances at once:

$ for pmonspid in `ps -eaf | grep [p]mon | awk '{print $2}'` ; do ps -f -p $pmonspid  ; grep "open files" /proc/$pmonspid/limits ; done
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle     545     1  0 Mar18 ?   00:08:27 ora_pmon_orcl1
Max open files            1024            1024           files <<< 1024!!
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle    1294     1  0 Apr20 ?   00:00:09 ora_pmon_orcl2
Max open files            1024            1024           files <<< 1024!!
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle    9917     1  0 Jan26 ?   00:08:17 ora_pmon_orcl3
Max open files            1024            1024           files <<< 1024!!
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle   11286     1  0 Jan26 ?   00:07:35 ora_pmon_orcl4
Max open files            1024            1024           files <<< 1024!!
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle   11647     1  0 Mar04 ?   00:04:36 ora_pmon_orcl5
Max open files            65536           65536          files
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle   11836     1  0 Jan26 ?   00:07:55 ora_pmon_orcl6
Max open files            1024            1024           files <<< 1024!!
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle   14183     1  0 Feb06 ?   00:07:13 ora_pmon_orcl7
Max open files            65536           65536          files
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle   16023     1  0 Feb27 ?   00:05:20 ora_pmon_orcl8
Max open files            65536           65536          files
UID        PID  PPID  C STIME TTY     TIME CMD           
oracle   18756     1  0 Mar20 ?   00:03:24 ora_pmon_orcl9
Max open files            65536           65536          files

If you find any wrong values, plan a restart before you encounter any error during peak hours!

—

Ludo