[hobbit] RRD and negative values

[Stef Coene]

On Monday 26 January 2009, doctor at makelofine.org wrote:
> Hi,
>
> I wrote a test reporting voltages from my motherboard's sensors. Those
> values are positives and negatives (+12V, -12V).
> I use split NCV to get values in different RRD files, and almost everything
> is OK, but I don't have any value for the negatives voltages. I added a -
> before the numeric value, but I don't get any value in RRD file :
> user at host:~$ rrdtool dump
> ~xymon/data/rrd/host/hardware,Negative_12V_volt.rrd  |head -50
> <!-- Round Robin Database Dump --><rrd> <version> 0003 </version>
>         <step> 300 </step> <!-- Seconds -->
>         <lastupdate> 1232991020 </lastupdate> <!-- 2009-01-26 18:30:20 CET
> -->
>
>         <ds>
>                 <name> lambda </name>
>                 <type> GAUGE </type>
>                 <minimal_heartbeat> 600 </minimal_heartbeat>
>                 <min> 0.0000000000e+00 </min>
>                 <max> NaN </max>
>
>                 <!-- PDP Status -->
>                 <last_ds> UNKN </last_ds>
>                 <value> NaN </value>
>                 <unknown_sec> 20 </unknown_sec>
>         </ds>
>
> Could someone told me how to work with negative values ?
Make them positive and put them the rrd.
If you createt the graph, you can make them negative again.


Stef