[rrd-users] step period, start and end

Simon Hobson linux at thehobsons.co.uk
Wed Sep 22 08:49:45 CEST 2010

Justin Carroll wrote:

>I am using GAUGE because I am looking for total water accumulation.

RRD Tool **ONLY** stores rates. You can calculate total from the rate 
very easily.

>My goal is to create a graph that only shows the MAX accumulation 
>for the day.  I was almost able to do this by setting a step time to 
>1day.  The problem is that the "step" doesn't go from midnight to 
>midnight.  In my case it goes from 6pm to 6pm the next day.

RRD Tool references everything to Unix Epoch - ie Midnight 1st Jan 
1970 UTC. If you have a 24 hour consolidation then it will ALWAYS 
start and end at midnight UTC. If you want a period other than that, 
you will need to keep a more detailed set of data and do things 
slightly differently.

Alternatively, you could fudge it by setting the timezone to UTC 
before doing each update and before doing each extraction. Ie, make 
RRD Tool think that the times you are feeding it are UTC rather than 
your real local timezone.

Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.

More information about the rrd-users mailing list