While restarting cpanel service from Terminal/Shell using command “service cpanel restart” if you are getting “cpsrvd dead but pid file exists”, please disable the Iptbales firewall of your linux Box and start “cpsrvd’.

Before that please check whether “cpsrvd” is running or not, using following command.

# ps aux|grep cpsrvd

root 30218 0.0 0.1 3012 724 pts/0 S+ 04:37 0:00 grep cpsrvd

If cpsrvd is running on the server then Iptables must be blocking the port cpanel currently running on and hence we need to disable the Default firewall of the Linux i.e., iptables.
But it is strongly recommended that firewall like CSF should be installed on the server to block “Failed Login Attempts”.

You can follow the steps given below :

1) service iptables stop
2) /usr/local/cpanel/cpsrvd
3) service cpanel restart
4) service cpanel status

Hope this will help !!