RRDtool

RRDtool is a command line utility designed for data graphing and logging of time series data that can be easily integrated in shell scripts, TCL apps or various programming languages, such as Python, Ruby, LUA or Perl. The idea behind the tool is to provide a more convenient way to store and manage this type of data. Not only can the application allow you to log or perform analysis for the data from numerous sources, but it can also generate graphical representations of it.

According to the developer, the app can come in handy for maintaining time-series data and, because it allows you to create graphs, you can easily create charts of the data stored. It can be employed for any type of software solution used to gather status information from a wide variety of things, such as the humidity and temperature in the office to octets that are passing through the FDDI interface of the router, hard disk DMA transfers, CPU temperature or SNMP monitoring data, for instance.

The tool is 100% open source and perhaps one of the most appreciated features is that the RRD databases you create use a compact binary format and act as the so-called Round Robin in nature. Since you can allocate the space for storing this data, you are averting the risk of disks getting full.