[rrd-users] How to "hide" RRDs with unknown or zero data?

[Alex van den Bogaerdt]

>> I am currently puzzled as to how to achieve the following...
>>
>> My RRDs have counts of message queues every minute. I want to display 
>> data
>> from all RRDs on the same graph for the same period of time (let's say
>> last 3 days). What i need is that if all values in specific RRD for this
>> time period are zero (or unknown) they should not be displayed on the
>> graph, and there should be no indication of the data in the key section.
>>
>> So, in the attached screenshot, i want to poll all RRDs but display only
>> the 4 that have positive data. Any suggestions on how this can be
>> achieved?
>>
>> All responses are greatly appreciated! Thank you in advance.


Okay,

A two-pass method:
Write a script (perl, bash, whatever you prefer to use) which
1: finds out for each of the DSes if the maximum value equals the minimum 
value equals either zero or unknown. rrdtool graph with some VDEFs should 
do, PRINT the results so that your script can access the values and compare.
2: generates a grapher script which graphs all DSes that do not match (1)

HTH
Alex