/etc/httpd/conf/httpd.conf – apache configuration file
/etc/exim.conf – mail server configuration file
/etc/named.conf – name server (named) configuration file
/etc/proftpd.conf – proftpd server configuration file
/etc/pure-ftpd.conf – pure-ftpd server configuration file
/etc/valiases/domainname – catchall and forwarders are set here
/etc/vfilters/domainname – email filters are set here
/etc/userdomains – all domains are listed here – addons, parked,subdomains along with their usernames
/etc/localdomains – exim related file – all domains should be listed here to be able to send mails
/var/cpanel/users/username – cpanel user file
/var/cpanel/cpanel.config – cpanel configuration file ( Tweak Settings )*
/etc/cpbackup-userskip.conf –
/etc/sysconfig/network – Networking Setup*
/etc/hosts –
/var/spool/exim –
/var/spool/cron –
/etc/resolv.conf – Networking Setup–> Resolver Configuration
/etc/nameserverips – Networking Setup–> Nameserver IPs ( FOr resellers to give their nameservers )
/var/cpanel/resellers – For addpkg, etc permissions for resellers.
/etc/chkserv.d – Main >> Service Configuration >> Service Manager *
/var/run/chkservd – Main >> Server Status >> Service Status *
/var/log/dcpumon – top log process
/root/cpanel3-skel – skel directory. Eg: public_ftp, public_html. (Account Functions–>Skeleton Directory )*
/etc/wwwacct.conf – account creation defaults file in WHM (Basic cPanel/WHM Setup)*
/etc/cpupdate.conf – Update Config *
/etc/cpbackup.conf – Configure Backup*
/etc/clamav.conf – clamav (antivirus configuration file )
/etc/my.cnf – mysql configuration file
/usr/local/Zend/etc/php.ini OR /usr/local/lib/php.ini – php configuration file
/etc/ips – ip addresses on the server (except the shared ip) (IP Functions–>Show IP Address Usage )*
/etc/ipaddrpool – ip addresses which are free
/etc/ips.dnsmaster – name server ips
/var/cpanel/Counters – To get the counter of each users.
/var/cpanel/bandwidth – To get bandwith usage of domain
WHM related files
/var/cpanel – whm files
+ bandwidth/ – rrd files of domains
+ username.accts – reseller accounts are listed in this files
+ packages – hosting packages are listed here
+ root.accts – root owned domains are listed here
+ suspended – suspended accounts are listed here
+ users/ – cpanel user file – theme, bwlimit, addon, parked, sub-domains all are listed in this files
+ zonetemplates/ – dns zone template files are taken from here