[rrd-users] wrong rra used

Alex van den Bogaerdt alex at vandenbogaerdt.nl
Sat Jul 5 01:26:10 CEST 2014

> As far as the 1hr offset (due to all summaries being done in UTC)  goes,
> there is no in-RRDtool solution.  We're in New Zealand so the offset is
> 12h or 13h, so it really shows!  If I remember correctly, Tobi mentioned
> about possibly addressing this issue in RRDTool 1.5 or later; it would
> probably require a new RRD format as there would be a timezone component
> to each RRA...
> If you really need to work around it, you might be able to extract
> per-hour data and summarise in your own code, but that still doesn't help
> for when you want a graph of one CDP per day.

The obvious workaround is to let the computer clock be equal to wall clock
time. Set the computer's timezone to UTC, disable NTP, and change it's
time to match your wall clock.

A similar effect can be achieved by massaging the timestamps for rrdtool
update, and running rrdtool graph (or rrdtool fetch) with TZ=utc (or
whatever is needed).

The problem is: what are you going to do when daylight saving starts or
ends. Not an easy task to tackle, but now you still have time to think and

More information about the rrd-users mailing list