Calculate Sum of Zabbix items

If you define a graph (as opposed to just clicking on an item and seeing the adhoc graph) you can specify that an item should be shown as its MAX value for the period represented by each pixel.

But if you are storing deltas (count per second) for things like traffic counters, printer page counters, etc., then you can also just use AVG and then do the following:

1. When you want to know the total for a period of time, graph the item over that period using an adhoc graph
   • Look at the average over the period (printed on the graph), and then multiply by the number of seconds in the period

You can use the rrdgraph command line tool to generate graphs using the rrd files that MRTG generates. You can inspect he rrd file and see how soon it is consolidating the data, if it does this only after a day then you will loose the resolution that you are after. So basically I would for where MRTG stores the rra templates and the rrd graph templates.

It might take you a little time but since RRD is the backend graphing library/toolset for MRTG, Cacti, Munin, etc it is worth learning. I blogged about some things you might want to do when creating your own graphs on the Server Fault blog here.

Hopefully someone more familiar with MRTG can give you more details on your specific issue with MRTG.