Further to my previous query, I have been experimenting with using step=1 and having one of my RRAs contain an hour's worth of 1-second values.
This has shown up another issue which is related to the "everything is a rate" philosophy of RRD. I am using a RRD GAUGE DS to log values which are not rates, but rather instantaneous values (e.g. disk space, channel usage, temperature). Let's say I log a value of 20 at time x. The input data changes to 25 at time y, so I log it at that time. I want the graph to show 20 from time x to time y and 25 from time y onwards. However, RRD is taking those values to be pre-derived *rates since the previous update*. So it is assuming the 25 means the average rate of something between time x and time y. So the graph is always one update adrift of the true change in values. The only way around this that I can think of is to remember the old value, and write it to the immediately preceding time. So in the above example, at time y I would write the old value of 20 to time y-1 and then the new value of 25 to time y. I'm using 1.0.49, just in case that is relevant. Is there any way, in that version or a newer version, to properly handle values that are instantaneous quantities rather than rates, without having to resort to the dual-write kludge I mentioned above? Thanks! Tony -- Tony Mountifield Work: [email protected] - http://www.softins.co.uk Play: [email protected] - http://tony.mountifield.org _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
