If you have a problem with either Monit or Munin, troubleshoot their log files. Monit’s main log file is located at /var/log/monit.log; and Munin’s log file directory should be at /var/log/munin/.
As an example, execute the grep FATAL /var/log/munin/* command to scan all Munin log files for FATAL errors. The following kinds of entry from /var/log/munin/munin-update.log come in handy when you want to learn more about the operation of Munin: 2018/08/01 12:05:01 [INFO]: Starting munin-update 2018/08/01 12:05:05 [INFO]: Munin-update finished (4.52 sec)
To see how often munin-update is executed, use grep and get the info from /var/log/munin/munin-update.log. The following entries verify that Monit‘ s process and its web interface have started: [EEST Aug 1 10:45:49] info: Starting Monit 5.25.1 daemon with http interface at [127.0.0.1]:2812 [EEST Aug 1 10:45:49] info: ‘ubu’ Monit 5.25.1 started