[rrd-users] Re: Fetching data from RRA's

[Tobias Oetiker]

Today you sent me mail regarding [rrd-users] Fetching data from RRA's:

*> To make certain I understand about the fetch command, consider the
*> following statements to create the db.
*> 
*> rrdtool create test.rrd -b 934495200 --step 600 \
*> DS:min:GAUGE:1200:1:3000 \
*> DS:avg:GAUGE:1200:1:3000 \
*> DS:max:GAUGE:1200:1:3000 \
*> RRA:AVERAGE:.5:1:144 \
*> RRA:AVERAGE:.5:12:48
*> 
*> The first RRA is supposed to contain a single data point every 10 minutes
*> for 24 hours.  The second RRA is supposed to contain data points based on
*> a running average of the previous 12 points.

correct 
*>  
*> Now, I assume that if I want to fetch the contents of the second RRA, I type:
*> 
*> rrdtool fetch test.rrd AVERAGE -r 7200
*> 
*> Since every data point is based on 7200 seconds (2 hours) worth of data.
*> However, I keep getting the data for the 24 hour RRA. Am I
*> misunderstanding something?  I did a dump and the data is definitely
*> there.

the way fetch is implemented its prime objective is to cover the whole time
range you are trying to fetch ... the second objective is to match the
resolution you requested ... 

as the two RRAs cover the same time range you may run into a problem there
... will check 

chers
tobi
*>   
*> Thanks,
*> Jim
*> 
*> 
*> --
*> * To unsubscribe from the rrd-users mailing list, send a message with the
*>   subject: unsubscribe to rrd-users-request at list.ee.ethz.ch
*> 
*> 

-- 
 ______    __   _
/_  __/_  / /  (_) Oetiker, Timelord & SysMgr @ EE-Dept ETH-Zurich
 / // _ \/ _ \/ / TEL: +41(0)1-6325286  FAX:...1517  ICQ: 10419518 
/_/ \.__/_.__/_/ oetiker at ee.ethz.ch http://ee-staff.ethz.ch/~oetiker

--
* To unsubscribe from the rrd-users mailing list, send a message with the
  subject: unsubscribe to rrd-users-request at list.ee.ethz.ch