How to view the logs
There are multiple ways to view log files, here are some common ways.
tail the log, shows the 10 most recent log entries.
tail /var/log/messages
tail the log and keep monitoring it for new entries.
tail -f /var/log/messages
Find specific info in log file
cat /var/log/messages | grep texttosearch
cPanel Log Paths
Main log
/var/log/messages
Access logs
/usr/local/cpanel/logs/access_log
Access logs for a specific domain
/home/user/access-logs/domainname.com
Account Transfers/miscellaneous logs
/var/cpanel/logs
Auditing Log (Account creation and deletions)
/var/cpanel/accounting.log
Backup Logs
/usr/local/cpanel/logs/cpbackup
CPHULKD Log
/usr/local/cpanel/logs/cphulkd.log
DNSAdmin, DNS Clustering
/usr/local/cpanel/logs/dnsadmin_log
Task Queue Processing Daemon
/usr/local/cpanel/logs/queueprocd.log
DBMapping
/usr/local/cpanel/logs/setupdbmap_log
Easy Apache Build logs
/usr/local/cpanel/logs/easy/apache/
Error logs
/usr/local/cpanel/logs/error_log /var/log/cpanel
License log
/usr/local/cpanel/logs/license_log
local database modifications
/usr/local/cpanel/logs/build_locale_database_log
Login errors CPSRVD
/usr/local/cpanel/logs/login_log
Bandwidth History
/var/cpanel/bandwidth/{USERNAME}
Service Status Logs
/var/log/chkservd.log
Tailwatch log
/usr/local/cpanel/logs/tailwatch_log
Update Analysis Reporting
/usr/local/cpanel/logs/updated_analysis/{TIMESTAMP}.log
Update log UPCP
/var/cpanel/updatelogs/updated.{TIMESTAMP}.log
cPanel Email Logs
Horde log
/var/cpanel/horde/log/
RoundCube
/var/cpanel/roundcube/log/
Squirrel Mail
/var/cpanel/squirrelmail/
Panic log
/usr/local/cpanel/logs/panic_log
Delivery and receipt log
/var/log/exim_mainlog
Incoming mail queue
/var/spool/exim/input/
Log of messages rejected based on ACLS or other policies
/var/log/exim_rejectlog
Unexpected/Fatal error log
/var/log/exim_paniclog
IMAP, POP login attempts, transactions, fatal errors and spam scoring
/var/log/maillog
Mailman
/usr/local/cpanel/3rdparty/mailmain/logs
MySQL
MySQL error log
/var/lib/mysql/{SERVER_NAME}.err
MySQL slow query log (if enabled in my.cnf)
/var/log/slowqueries