Maybe I do not get to understand something, let me explain: setting 'Steps' field to 1 in RRA definition mean you don't use consolidation at all. But you need anyway to fill in the 'Consolidation Functions' field (average, min, max or last) which means that you do use a consolidation function, so what's the point, either you use it or not ? If you set 'Steps' to 1 and in addition select one or several consolidation functions wouldn't there be a bug, some kind of conflict ?
But I do not understand, if you're aiming at capacity planning, why you want to have 30 sec intervals for a whole year.
Well this is about 'needs definitions', coming from my boss: he wants to have a 30 seconds granularity for at leats the 3 past months (maybe 6 months, not a whole year in fact).
But when consolidating both AVERAGE and MAXIMUM, you will be able to deduce volume capacity information (AVERAGE) and peak capacity consumption (MAXIMUM) as well. MAXIMUM consolidation will not loose the exact overall MAXIMUM value of the consolidation interval. It will only loose the exact time when this MAXIMUM occured! In most cases, for capacity issues this will be fine. Only for debugging purpose, when it is crucial to correlated events on the timeline, consolidation will loose vital information.
Well in fact I used your tutorial (very well done by the way !) "Howto define a very BIG rra without data loss" located here:
where it's suggested to only use the AVERAGE consolidation function. But I don't understand why using only this one since in all default RRAs, both AVERAGE and MAXIMUM are selected. The few I understand is that if I use only average I will not lose the maximum values time occurrence, but I will lose the average values time occurrence. I can't understand what is the consequence to this... I've just been thinking of this: the best for me would be to select no consolidation functions in RRAs definitions so that only exact values are stored and graphed. Would this be smart or not ?
Anyway, thank you very much for your answers, it helps me going fast in my Cacti deployment