Multi-rrd graphs

[Vernon Everett]

Hi all

OK, I am probably pushing the envelope here, but maybe it's possible.

Lets assume I am collecting data about some disks.
Or maybe we don't assume. I am doing it.
As data, I am collecting
    % Cache hits
    % Reads
    % Writes
Using split NCV, I get a bunch of files.
cache,vol01.rrd
cache,vol02.rrd
cache,vol03.rrd
cache,vol04.rrd
read,vol01.rrd
read,vol02.rrd
read,vol03.rrd
read,vol04.rrd
write,vol01.rrd
write,vol02.rrd
write,vol03.rrd
write,vol04.rrd

Using the standard graph definitions, I can get all the cache values
on one graph, all the read values on another etc. etc.
Is there a way to group them by the volume name?
So I end up with a graph of cache, read and write for vol1 on one graph.
The cache, read and write for vol1 on another etc. etc.

Of course, in reality, I have far more than vol01-04, and they are not
all volXX either, so hard coding the hobbitgraph.cfg entry isn't an
option.

Possible?

Regards
     Vernon.