Munin is probably the best known open source server monitoring tool. It is relatively easy to set up from memory, I think it was just a case of uncommenting a l

Munin is probably the best known open source server monitoring tool. It is relatively easy to set up from memory, I think it was just a case of uncommenting a load of config lines for the things you want to monitor in the standard Ubuntu package. http://munin-monitoring.org/ http://munin-monitoring.org/