Your issue seems to have been that the munin-node service was not running: [12:59:35 mail root@9469293 ~]cPs# systemctl status munin-node.service ● munin-node.service - Munin Loaded: loaded (/etc/systemd/system/munin-node.service; enabled; vendor preset: disabled) Active: failed (Result: timeout) since Sat 2018-04-21 21:58:40 CEST; 5 days ago Apr 21 21:57:07 mail.ebs.dz systemd[1]: Starting Munin... Apr 21 21:57:09 mail.ebs.dz systemd[1]: PID file /var/run/munin/munin-node.pid not readable (yet?) after start. Apr 21 21:58:40 mail.ebs.dz systemd[1]: munin-node.service start operation timed out. Terminating. Apr 21 21:58:40 mail.ebs.dz systemd[1]: Failed to start Munin. Apr 21 21:58:40 mail.ebs.dz systemd[1]: Unit munin-node.service entered failed state. Apr 21 21:58:40 mail.ebs.dz systemd[1]: munin-node.service failed. I restarted that service for you: [12:59:51 mail root@9469293 ~]cPs# systemctl start munin-node.service [13:00:04 mail root@9469293 ~]cPs# systemctl sta...