Sentinel server log is showing the error "To many files open" Webui will not open

  • 7022134
  • 19-Oct-2017
  • 14-Nov-2017


Sentinel on RHEL 6.9


Sentinel logs are showing the error “Too many open files (24)” because the application/command/script is hitting the maximum open file limit allowed by Linux.


ncrease limit
Per-User Limit

Open file: /etc/security/limits.conf

Paste following towards end:

*         hard    nofile      500000
*         soft    nofile      500000
root      hard    nofile      500000
root      soft    nofile      500000
500000 is a good number. It can be increased to a higher number but it can start using alot of memory if it is set to high.

If above changes are not working try adding the following.

Open /etc/pam.d/common-session

Add following line:

session required

Once the file is saved,logout and login again.System-Wide Limit

Set this higher than user-limit set above.

Open /etc/sysctl.conf 

Add following:

fs.file-max = 2097152

sysctl -p
the above will increase “total” number of files that can remain open system-wide.

Verify New Limits
Use following command to see max limit of file descriptors:

cat /proc/sys/fs/file-max
Hard Limit

ulimit -Hn
Soft Limit

ulimit -Sn
if you are logged in as root:

Check limit for other user

Just replace www-data by the tlinux username you wish to check limits for:

su - www-data -c 'ulimit -aHS' -s '/bin/bash'
Check limits of a running process:

Find process-id (PID):

ps aux | grep process-name
Suppose, XXX is PID, then run following commands to check limits:

cat /proc/XXX/limits