[rrd-users] Graph from data with holes.possible?
linux at thehobsons.co.uk
Wed Jun 1 10:00:03 CEST 2011
>I have performance data taken at 15min steps during the whole 24h day. (nmon
>tool for AIX)
>Now,I´d like to graph data for only the day shitf (8AM-8PM), so I'd like to
>say rrdtool "get data just for this hours interval and forget the rest".
>After some testing, i don´t know how to do it.Do you have an idea? If there
>is a 12h gap among my rrd data for each day,will be rrdtool capable of doing
>graphs without holes?
If you mean you want a graph that runs from 8am
to 8pm, and then without a gap jumps to 8am the
next day - then no, rrd tool cannot do that.
You could however draw a graph that shows no data
between 8pm and 8am by using a calculation along
the lines of :
if time between 8am and 8pm then plot_data=source_data else plot_data=unknown
Calculations such as averages would correctly
take account of the unknown values (provided you
use the correct function), but you would have big
gaps in the grpahs.
If you really want the former, then you would be
best using rrd to collect the data and store it,
then export the data and use an external plotting
program to generate the graphs.
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