Consider the RRD database file [prova.rrd][]. It contains two data sources:
total
, always reporting about 4 M of "something" (kbyte RAM)used
, showing an increase from about 200 k to about 2 M over a 10-years period.
There are aggregation at multiple levels, one over the span of 10 years.
The stand-alone graph for used
is the following, showing the increase over time: