rrdtool resize filename rra-num GROW|SHRINK rows
The resize function is used to modify the number of rows in an RRA.
The new .rrd file, with the modified RRAs, is written to the file resize.rrd in the current directory. The original .rrd file is not modified.
It is possible to abuse this tool and get strange results by first removing some rows and then reinserting the same amount (effectively clearing them to be Unknown). You may thus end up with unknown data in one RRA while at the same timestamp this data is available in another RRA.
Alex van den Bogaerdt <email@example.com>