Disc IO for query in MongoDB is there a way to tell how much data MongoDB is reading from disc and how much from cache for a query ?
I looked at the explain()-Function but did not find this kind of informations.

Thanks, Andre
It is not possible per request, but you might want to give the free MMS a try, which has quite some metrics. Together with the hardware monitoring provided by munin-node, you get a pretty good picture on what's going on on your MongoDB servers.