HOWTO remove spikes from RRD graphs

If you happen to use rrdtool to create graphs to monitor equipment you might have come upon some “spikes” in your graphs. These are perfectly normal and happend due to machines that have rebooted and have reset their counters or other anomalies that might occur.
There is a script called removespikes.pl made specially to fix these cases. You can either find the tool here: http://oss.oetiker.ch/rrdtool/pub/contrib/removespikes.tar.gz or get it from my blog removespikes.pl.gz
Extract it, and then type something in the command line like the following:
for i in /location/of/rrds/*; do /full/path/to/removespikes.pl $i; done;
You should probably see some messages like these:

Chopping peak at <!– 2005-10-25 17:00:00 EEST / 1130248800 –>
Chopping peak at <!– 2005-10-25 19:00:00 EEST / 1130256000 –>

That’s all…enjoy your graphs.