It is pretty easy to gather status information from all sorts of things, ranging from the temperature in your office to the number of octets which have passed through the FDDI interface of your router. But it is not so trivial to store this data in a efficient and systematic manner. This is where RRDtool kicks in. It lets you log and analyze the data you gather from all kinds of data-sources. The data analysis part of RRDtool is based on the ability to quickly generate graphical representations of the data values collected over a definable time period.