Background I switched server OS from Uuntu 24.04 to Debian 12 bookworm. After updates, among priorities, I installed fail2ban utility to prevent sshd attack. It turned out a failed process.  At the /etc/fail2ban directory, a copy of fail.conf was made fail.local, a traditional practice. Fail2ban showed an error exit code: root@xxxxxxxxx:/etc/fail2ban# systemctl restart fail2banroot@xxxxxxxxx:/etc/fail2ban# systemctl […]