How to see historical root logins to a server
Command: last -F | grep root journalctl _COMM=sshd | grep root
journalctl
How to vacuum journalctl
How to free up space if your Linux journal (combined log file) is taking up a lot of space On some systems /var/log might be
Postfix suddently stops logging on CentOS – rsyslog versus journalctl
Issue Encountered Postfix works but doesn’t seem to log anymore. tail -f /var/log/maillog shows nothing and nor does /var/log/mail.log. Sadly, this used to work. Eventually