[rrd-users] counting pellets with rrd
m at box.li
Sat Dec 10 22:35:04 CET 2011
Simon Hobson schrieb:
> Matthias Lemke wrote:
>> I connected my eta pellets heating unit via webservices to my home
>> server. I am interesting in counting the amount of pellets per day (warm
>> weather days should have low counts of pellets). The unit has a counter
>> that counts from zero up forever... The unit sends the value in "kg".
>> normally I have around 15...20 kg / day.
>> I want to have a graph that shows me the kg/day. So I thought that I can
>> write one data per day to the rrd. But, after two nights of testing and
>> testing, I have no idea for the correct rrd setup...
>> Do You have any hints for that challenge :) ?
>> I want to have two RRAs:
>> one vor 400 days, one data per day (kg/day).
>> second one for kw/weeks for 500 weeks...
> Firstly, remember that RRD stores <things> per second. No matter what
> you feed it, that's what it stores.
I remember that from my network usecases (bytes/second)... ok.
> So lets say you feed it a value once per day, and the value is 15kg -
> then rrd will convert that to 15/86400 = 1.736e-4 (or 0.0001736)
> kg/s. Your options are really to multiply by 86400 before storing the
> value, or on extracting the data.
what do You mean with "extracting the data"?
multipliing was one of the idea.... right.
> Another issue is that rrd works in UTC, so the "days" it will work
> with are not the same as your local days. You just need to be aware
> of that.
good point, thanks.
> You will want a counter data type since you conveniently have a
> counter to feed it with.
More information about the rrd-users