iRedMail — Fail2ban Log Filled With Command Not Found Errors + Fix

Re: Fail2ban Log Filled With Command Not Found Errors + Fix

null@example.com (tiobuck) — Thu, 24 Jul 2025 06:00:04 +0000

Thank you!

Re: Fail2ban Log Filled With Command Not Found Errors + Fix

null@example.com (ZhangHuangbin) — Wed, 23 Jul 2025 01:58:15 +0000

Looks like cron job runs BEFORE mariadb service is running. It's safe to ignore.

Re: Fail2ban Log Filled With Command Not Found Errors + Fix

null@example.com (tiobuck) — Tue, 22 Jul 2025 20:37:56 +0000

ZhangHuangbin wrote:

Seems failed to connect to SQL server.
Does it failed every time when it blocks an IP?

No, logs are clean. I did a test doing a full server reboot vs restarting the fail2ban service. The errors only occur on a fresh boot of the system. They don't appear if I restart the fail2ban service. Timeout perhaps? I'm renting an older dedicated server (intel core 2 duo 2GHz, 4GB RAM, 250GB HDD).

Re: Fail2ban Log Filled With Command Not Found Errors + Fix

null@example.com (ZhangHuangbin) — Tue, 22 Jul 2025 02:15:04 +0000

Seems failed to connect to SQL server.
Does it failed every time when it blocks an IP?

Re: Fail2ban Log Filled With Command Not Found Errors + Fix

null@example.com (tiobuck) — Mon, 21 Jul 2025 16:49:52 +0000

My apologies, I saw the previous issue pavel.kasparak reported about fail2ban. I did the fix you recommended. It cleaned up the logs but I noticed an error in consecutive lines during fail2ban startup:

fail2ban.utils[409]: ERROR 7f36808743f0 -- exec: /usr/local/bin/fail2ban_banned_db start sshd

fail2ban.utils[409]: ERROR 7f36808743f0 -- stderr: "ERROR 2002 (HY000): Can't connect to server on '127.0.0.1' (115)"

fail2ban.utils[409]: ERROR 7f36808743f0 -- returned 1

fail2ban.actions[409]: ERROR Failed to start jail 'sshd' action 'banned_db': Error starting action Jail('sshd')/banned_db: 'Script error'

Re: Fail2ban Log Filled With Command Not Found Errors + Fix

null@example.com (tiobuck) — Sun, 20 Jul 2025 16:57:00 +0000

Yes sir

Re: Fail2ban Log Filled With Command Not Found Errors + Fix

null@example.com (ZhangHuangbin) — Sat, 19 Jul 2025 15:06:06 +0000

Does your server have /usr/bin/env?

Fail2ban Log Filled With Command Not Found Errors + Fix

null@example.com (tiobuck) — Fri, 18 Jul 2025 18:21:34 +0000

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.7.4
- Deployed with iRedMail Easy or the downloadable installer? No
- Linux/BSD distribution name and version: Debian 12
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
Snippet:
2025-07-17T22:01:33.958862+00:00 mail fail2ban.utils[403]: ERROR 7fe3f54b2790 -- returned 127
2025-07-17T22:01:33.958916+00:00 mail fail2ban.utils[403]: INFO HINT on 127: "Command not found". Make sure that all commands in '/usr/local/bin/fail2ban_banned_db start pregreet'
====

Did a fresh install yesterday and noticed errors in Fail2ban log. Found a path error to bash in line 1 of /usr/local/bin/fail2ban_banned_db.

Stopped fail2ban service. Changed 1st line of fail2ban_banned_db to #!/bin/bash. Restarted fail2ban. Logs are clean now.