Hello Markus,
We are migrating from Cacti to Observium and it was a great experience, the only thing we lacked were the weathermap plugin for getting that nice network overview. I then found that Neil Lathwood wrote a modified version of the PHP Weathermap that works with Observium data, you can find it on his github: https://github.com/laf/weathermap [1]
I wrote a quick and dirty script that adds the weathermaps to the Observium menu without modifying Observium-code so that it will not break when updating Observium. It works really well so I wrote a little guide for how you get the weathermap to work with Observium and posted it here: http://blog.best-practice.se/2014/07/using-php-weathermap-with-observium.htm... [2] In case there are more people interested in using the weathermap with Observium :)
Maybe it's just me, but I do not have a /opt/observium/html/include/ directory, shouldn't that be includes?
If I copy the navbar-custom.inc.php from the weathermap directory to that includes directory, Observium doesn't even load the interface properly...
I'm using the latest Observium version.