[rrd-users] gprint last_ds value

Simon Hobson linux at thehobsons.co.uk
Tue Dec 1 08:53:50 CET 2009

At 18:14 -0800 30/11/09, Nathaniel R. Ben-Attar wrote:
>I am using a shell script to poll data from a mysql database. 
>That script returns a numeric value that is being picked up properly 
>by my data template and recorded in the rrd.
>'rrdtool info' shows:
>rrd_version = "0003"
>step = 300
>last_update = 1259633148
>ds[datavalue].type = "GAUGE"
>ds[datavalue].minimal_heartbeat = 600
>ds[datavalue].min = 0.0000000000e+00
>ds[datavalue].max = NaN
>ds[datavalue].last_ds = "475.00"
>ds[datavalue].value = 2.2800000000e+04
>ds[datavalue].unknown_sec = 0
>The value for last_ds (475.00) is the correct value returned by the 
>script.  I want to display this value below a graph.  I use gprint 
>with LAST and EXACT.  The value displayed is NOT 475.00.
>Is there something I'm missing?

rrdtool does not store exact values except under certain specific 
conditions. See Alex's tutorial on normalisation at

Simon Hobson

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