Most probably, Munin HTTP server isn't accessible from the host on which you're viewing Ajenti. This will be fixed in 1.x by proxying images through Ajenti.
Thanks for your comment Eugeny. You're right the Munin HTTP server wasn't accessible because of the apache's IP restrictions made by myself... (Shame on me)
Still cant see the graphs, can see them from localhost/munin... cant see them on ajenti
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