RRDTool does not create a consolidation 'on the fly'. Therefore, if you need a particular average, you need ot add an RRA.
Why is this? Because, RRDTool is optimised for rolling up averages. As averages are consolidated, data is lost, so it is quite likely that you cannot mathematically determine an average over a different resolution. Also, the colsolidation is the 'expensive' part, so by doing this progressivly as theupdates come in the performance is improved. You specify a resolution in the FECTH or GRAPH because there may be more than one possible resolution at the requested time interval, if you have multiple RRAs that cover it. If an exact match is not available, RRDTool will use the closest available match. Hope this helps, Steve Steve Shipway University of Auckland ITS UNIX Systems Design Lead [email protected] Ph: +64 9 373 7599 ext 86487 ________________________________________ From: [email protected] [[email protected]] on behalf of LE GONIDEC Romain [[email protected]] Sent: Friday, 23 September 2011 2:47 a.m. To: '[email protected]' Subject: Re: [rrd-users] RRDTool Fetch : Recover data with a different resolution of the RRA I am therefore obliged to add an RRA? RRDtool can not calculate your own? Why then specify a resolution. Only suffient timestamp. _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
