For example, I want to graph the largest of three datasources. What I want to do is this:
The problem is that I can't get Cacti to create the DEF lines unless I give it LINE[123] graph items./usr/local/bin/rrdtool graph - \
--imgformat=PNG \
--start=-86400 \
--end=-300 \
--title="High phase current" \
--base=1000 \
--height=400 \
--width=600 \
--alt-autoscale \
--vertical-label="Current, Amps" \
DEF:a="/usr/local/www/data-dist/cacti/rra/ALC/Emon/1m.rrd":I_A:AVERAGE \
DEF:b="/usr/local/www/data-dist/cacti/rra/ALC/Emon/1m.rrd":I_B:AVERAGE \
DEF:c="/usr/local/www/data-dist/cacti/rra/ALC/Emon/1m.rrd":I_C:AVERAGE \
CDEF:cdefd=a,b,GT,a,b,IF,c,GT,a,b,GT,a,b,IF,c,IF \
LINE3:cdefd#000000:"max phase"
I've seen people post that drawing with white lines is the solution, but that screws up my scaling and any background colors I may apply (by using CDEFs and AREA items).
These graphs would have to be opaque to the UI somehow, I suppose, but at least I could place them on the trees.
Thanks.