When we reach the end of the database, it will wrap back to the begin again.
This means that RRD database files will never grow in size.
You can still use the command line version of RRDTool to try all examples.
You may not be familiar with the term RRD graph, but if I show you one, you probably recognize them instantaneously.
They are used to plot all kind of data against time in a very easy way which is why they are used a lot in all kind of applications.
Even though many consider RRD as a library to create graphs, it is actually more than that: it’s a complete system to store aggregated data in a very efficient way. It is a database for collecting all kinds of data against time.The “round robin” stands for the fact that only a certain amount of “data points” can be stored.On a Debian or Ubuntu system there is no default package but it’s very easy to build from the source.If you cannot build the extension or you cannot find anything working, no fear.
This doesn’t mean you only can add data every 5 minutes though.You can add as much data into the RRD and at any time you like. If you have a default step rate of 5 minutes but you add some data every minute to your RRD, it will average these 5 values into 1 data point.