What is Cacti?
Cacti is a tool for network data collection, storage and presentation. It provides a frontend to many of the functions of rrdtool (which is used for the underlying data storage and graph generation), as well as the interfaces for managing the configuration and graph presentation. Data is collected from remote devices on a regular interval (usually every 5 minutes) and stored in Round Robin Archives (RRA's), which are special-purpose data files. The stored data can then be retrieved and graphed in real-time.