Thanks for your reply Dan. I don't really understand how I could be experiencing counter roll-overs? This would be an issue when a 32 bit counter wraps around in less than 5 minutes, which cannot be happening on my fast ethernet interfaces (which btw don't even go above 10% utilization).
My MRTG config looks like this: one target for each interface (as generated by cfgmaker) and finally after all individual interfaces I added the total, by simply copy/pasting the target of each of the above interfaces with + signs in between. >From the documentation I learned that MRTG is smart about multiple occurrences of the same target in a configuration file: it will not query a second time but reuse the previously saved value. So all my individual values are fine and it's up to MRTG to add them up, and at this stage I cannot imagine that counter wrap is still an issue - surely MRTG (well, Perl I guess) is capable of handling this properly and is not just adding up my 8x32 bit counters into a single 32bit counter? Besides, wouldn't counter wrap result in _lower_ values than expected? (what I see is about 3 times _higher_ values than I should get). Anyway if that's what happening then I don't understand the point of being able to add/subtract/divide targets in MRTG if it doesn't work? (what I'm doing is exactly the example given in the MRTG docs, aggregate a few interfaces together, only I have 8 of them and not 2). Thanks a lot for your time! Rgds pvh McDonald, Dan wrote: > > On Wed, 2009-02-11 at 05:19 -0800, pvh wrote: > >> 1:commun...@ip + 2:commun...@ip + 3:commun...@ip .. > > So, when one counter rolls over, mrtg has no way of knowing (and > correcting) > >> I'm working with fast ethernet interfaces (all 32 bit counters) here. > > Thus rollovers are frequent. > > The only way to accurately do this is to collect the three counters > separately, and use routers2.cgi (or some other similarly enlightened > front end, but there aren't any others published with this feature) and > build a stacked graph to show the actual total. > > Note that that requires RRDtool as a backend > > -- > Daniel J McDonald, CCIE #2495, CISSP #78281, CNX > Austin Energy > http://www.austinenergy.com > > > > _______________________________________________ > mrtg mailing list > [email protected] > https://lists.oetiker.ch/cgi-bin/listinfo/mrtg > > -- View this message in context: http://n2.nabble.com/totals-do-not-add-up-when-graphing-multiple-targets-tp2308575p2315640.html Sent from the MRTG Users Mailinglist mailing list archive at Nabble.com. _______________________________________________ mrtg mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/mrtg
