fail2ban seems to accumulate records in sqlite database forever.
https://github.com/ffzg/fail2ban-helpers
dpavlin@mjesec:/var/lib/fail2ban$ ls -alh total 165M drwxr-xr-x 2 root root 4.0K May 12 2020 . drwxr-xr-x 82 root root 4.0K May 12 2020 .. -rw------- 1 root root 165M Nov 30 09:30 fail2ban.sqlite3 dpavlin@mjesec:/var/lib/fail2ban$ sqlite3 fail2ban.sqlite3 Error: unable to open database "fail2ban.sqlite3": unable to open database file dpavlin@mjesec:/var/lib/fail2ban$ sudo sqlite3 fail2ban.sqlite3 sqlite> select datetime(min(timeofban),'unixepoch'),datetime(max(timeofban),'unixepoch') from bans ; 2020-05-12 18:25:57|2020-11-30 08:34:41
dpavlin@syslog:~$ cat /etc/cron.daily/fail2ban-sqlite #!/bin/sh sqlite3 /var/lib/fail2ban/fail2ban.sqlite3 "delete from bans where timeofban <= strftime('%s', date('now', '-30 days'));" sqlite3 /var/lib/fail2ban/fail2ban.sqlite3 "vacuum;"