Sooner or later when doing some bigger system or just by messing with os you will meet that error:
Too many open files
You can solve it quickly by:
vi /etc/sysctl.conf
Append a config directive as follows:
fs.file-max = 200000
Save and close the file. Users need to log out and log back in again to changes take effect or just type the following command:
# sysctl -p
Verify your settings with command:
# cat /proc/sys/fs/file-max
vi /etc/security/limits.conf
Set admin user (or for any other user) soft and hard limits as follows:
admin soft nofile 200000
admin hard nofile 200000
Done