> Hi folks, > I am new to RRD and still trying to wrap my mind around the power of > this > excellent tool. I am working on an application to use RRD to store > electricity meter data for a group of homes. I am expecting to create an > RRD file for each home, and it will have a number of RRA's defined for > various time periods.
Good. I suggest you store Joules, or kilowatthours. > In addition to displaying the individual house data graphs, I would like > to also create graphs that show aggregated results drawn from the house > RRD files. For example, I might show the combined power draw in watts for > the 8 homes that make up a quadrant of my neighborhood, or show the total > power draw from all 30 homes. > > Is there a reasonably-straightforward way to do this in RRD? DEF:meter1=/home/user/data/rrd/house1.rrd:meter:AVERAGE DEF:meter2=/home/user/data/rrd/house2.rrd:meter:AVERAGE DEF:meter3=/home/user/data/rrd/house3.rrd:meter:AVERAGE [...] CDEF:total=meter1,meter2,meter3.... [...] LINE1:total#000:total There are several things to improve in this (incomplete) example, but what I show here is the answer to your question: how to combine data from several sources. Another example (using the same DEFs): [...] AREA:meter1#F00 AREA:meter2#FC0::STACK AREA:meter3#0C0::STACK AREA:meter4#F00::STACK [...] _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users