[rrd-users] New with rrdtool - data is not plotting to graph

[Ben]

Hi,

Any feedback please.

BR
Ben
> Hi,
>
> I am new with rrdtool. I am making a graph for our application which 
> provides cumulative data. So for them analysis, I use derive DATA 
> SOURCE TYPE. Derive DST means : always take difference from current 
> value and last value.
>
>
>  my rrd command :
>     rrdtool create a.rrd \
>     --step 60 \
>     DS:A:COUNTER:120:0:U \
>     RRA:AVERAGE:0.5:1:7200
>
> rrd update command :
>
>     logger rrdtool update a.rrd N:$A
>     it shows each time value in syslog, so it is working fine.
>
> rrdtool graph a.png -a PNG \
>     --title="Info" -w $Width -h $Height \
>     --watermark "`date`" \
>     'DEF:A=a.rrd:A:MAX' \
>     'LINE:A#00dd00:A' > /dev/null
>
>     it generates blank graph.
>
>
>     Where i did mistake, please provide your feedback.
>
>     One confusion from me : RRA stands for Round Robin Archive, so 
> when we should use MAX/MIN/AVERAGE/LAST with RRA? Please provide some 
> example.
>
>     BR