I use RRDtool to make graphs on various things I monitor like server stats, network stats and it does a relatively good job. My one (big) complaint is that when you restart you occasionally see these gigantic spikes that completely mess up the data. I’ve even seen spikes larger than what the system can technically handle.
Nobody mentioned there’s a removespikes.pl script (download) that will remove these outliers from your rrds. I put together a quick shell script to make it quick for when I need to run it again:
!/bin/sh
for i in /path/to/graphs/rrd/*;
do
perl removespikes.pl $i;
done;
If you have a ton of graphs a quick shell script to iterate through the directly may be quicker. If you only have a handful like me, no big deal.
Keep the script around for the next time you have spikes to deal with.
