Munin not showing stats or running updates

Symptoms

Munin's graphs either do not show or do not get updated.

Description 

There are several reasons that the Munin graphs do not get updated. The most common reasons are incorrect ownership or permissions on Munin's files.

Workaround

Please note, if mistakes are made applying the workaround you could potentially damage your server. If you are unfamiliar with the command line and the dangers of changing file ownership and permissions, you should consult  system administrator who can make the change for you.

1. Ensure that /etc/munin/munin.conf is owned by the user and group and has the permissions set to 644.

   chown root:root /etc/munin/munin.conf

   chmod 644 /etc/munin/munin.conf

2. Ensure that /var/lib/munin/plugin-state/nobody/ is owned by munin:munin and has permissions 755.

   chown munin:munin /var/lib/munin/plugin-state/nobody

   chmod 755 /var/lib/munin/plugin-state/nobody

3. Ensure that the files under /var/lib/munin/plugin-state/nobody/ are owned by nobody:munin and have permissions set to 600.

   find  /var/lib/munin/plugin-state/nobody  -type f -exec chown -v nobody:munin {} \;

   find /var/lib/munin/plugin-state/nobody  -type f -exec chmod -v 600 {} \; 

Additional Resources

How do I change permissions on a file or folder?

How to change ownership of a file or directory