[rrd-users] Bits/sec and GB/month

Eric eric at mailinator.com
Mon Oct 20 15:24:49 CEST 2008

Hello group!

Currently I'm not an rrdtool user but, my co-lo provider uses RRD for their
bandwidth monitoring. Since recently they are providing me graphs with an
Y-axis which as 'bits per second' and an X-axis which provides the time. 
On top (seperate graphic) there is a seperate graph which is tabular and
provides me GB/month and MB/day.

The problem is that this data is completely wrong (they are trying to overbill
me for 800%) when I compare this number with the number of network packets on
my NIC, or when I do 'live tests' with sending data and comparing this with
their graphs. I'm trying to figure out how they are making this mistake.

Unfortunatly they are behaving very closed to giving me details but I already
figured out they are using 'GBGraph2' to calculate the totals, a small 
abandoned project. Unfortunatly I can't find a lot of info about it anymore.

As far as I understand, RRDTool never saves real data but only data from
points in time. So, if somebody is making graphs with 'Bits/seconds' and
stores this data in an rrdtool database, you cannot calculate back to totals,
unless assuming the average for the default time of 5 minutes, was the same
those 5 minutes and multiply this average by 5*60. By this, bandwidth bursts
are heavily punished.

So, since they are telling me their totals are coming from their rrdtool
database, I think they provide me impossible values.

I'll try to setup a similar setup to test out my thoughts, but if in the
meanwhile anybody has experience in this matter or thoughts, you are 
welcome to give me your thoughts :-)


More information about the rrd-users mailing list