[rrd-users] rrd create update problem

Simon Hobson linux at thehobsons.co.uk
Mon Jul 26 11:18:32 CEST 2010

homephilsch at gmx.de wrote:
>My crontab entry:
>30 0 * * * updateRRD.sh
>As you can see the crontab runs successfully (see lastupdate).
>So my question is why I have only NaNs in the dump?

Because you haven't supplied enough updates to "finish" a step 
period. Specifically, you've updated at 00:30 for a bin that doesn't 
finish until 02:00.

>Why the start time is at 02:00:00 (is the difference caused by the 
>UTC-CEST difference )?


>  Is it correct to have the heartbeat set to 172800 or should I set 
>it to a smaller number?

That entirely depends on your needs.

>I read many tutorials on the web about the rrdtool but I could not 
>figure out why my rrd database isn't updated correctly.

See http://www.vandenbogaerdt.nl/rrdtool/
In particular, see the tutorial on "Rates, normalizing and consolidating"

Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
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