Some important logs and config files location
The common logs files located here /usr/local/cpanel/logs directory.
cPanel access log for both cPanel and WHM
/usr/local/cpanel/logs/access_log
cPanel error log (This file contains all output from each upcp call. logs are stored with the timestamp from which the upcp process was executed)
Web server (Apache) log (This log file contains all the errors caused by http Apache server, standard errors due to domain's virtual configuration, mod_security, PHP Warning and other apache modules configurations)
/usr/local/cpanel/logs/error_log … Read the rest