Munin is an excellent system monitoring tool similar to RRD tool which will give you ample information about system performance in multiple fronts like disk, network, process, system and users.
These are some of the default properties Munin monitors. How Munin works? Munin works in a client-server model. Munin server process on main server try to collect data from client daemon which is running locally(Munin can monitor it’ss own resources) or from remote client(Munin can monitor hundreds of machines) and displays them in graphs on its web interface. Configuring Munin in nutshell