I have a new Ubuntu server (Ubuntu 16.04.1 LTS, server version without GUI, running as a virtual server in a remote server farm), and I installed munin on it (munin and munin-node). I did not change anything from the standard installation, so at the moment I use the 30 plugins that are part of the standard installation. 28 of them worked fine from the beginning.
The plugin "HTTP load time of a page" showed an empty graph, but I found out that the package time
was missing. I installed it with
apt install time
and restarted munin-node. So now this plugin is fixed.
But there still is a problem with »processes priority« (plugin »proc_pri«). The graphs of this plugin (by day, by week, ...) are all empty, and I have now idea where I could start to search for the reason of this problem.
Please can you give me some hints what I could do to fix this problem? Or what I could do to isolate the problem.