[rrd-users] Adding an element to a graph

[Cole Tuininga]

Hi all,

I'm dynamically building an rrdgraph call after my program hunts
around for several rrd files to aggregate from.  The problem is that
the requested data won't always have any rrd files, but I still want
to have it available as an item in the graph.

My thought was to create a placeholder CDEF - something like

CDEF:placeholder=0
or, if necessary
CDEF:placeholder=0,0,+

So that I can do a:

LINE:placeholder#0000FF:Blah

However, these don't seem to work.  It's not enough to simply add in
an "extra" item to the legend without graphing the data - this may be
the only item.  In that scenario, no graph would be generated, so
there would be no legend to add to.  :)

Thanks in advance for any help.

-- 
Cole Tuininga
http://www.tuininga.org/