Clarence Hart wrote: > > Why do I get different values when I make my start and end times > over aprox 13days? > -> If I choose to graph 5 days the max value would be 140 pages. > -> If I choose to graph 20 days the max value would change to ~70 > pages. > > Why does this happen?
If you are working with the AVERAGE values, any peaks in the data will be flattened out. For instance: A five-minute sample rate and also 5 minutes per row in the RRA. t+00:05 value 120 (valid for interval t+00:00 to t+00:05) t+00:10 value 80 (valid for interval t+00:05 to t+00:10) t+00:15 value 100 (valid for interval t+00:10 to t+00:15) t+00:20 value 100 (valid for interval t+00:15 to t+00:20) If you fill two RRAs using this data, you'll get: t+00:05 average 120 maximum 120 (valid for t+00:00 to t+00:05) t+00:10 average 80 maximum 80 (valid for t+00:05 to t+00:10) t+00:15 average 100 maximum 100 (valid for t+00:10 to t+00:15) t+00:20 average 100 maximum 100 (valid for t+00:15 to t+00:20) If this is consolidated into an RRA with 20 minutes per row, and there is such an RRA for MAXIMUM values and one for AVERAGES, you get two different numbers: t+00:20 average 100 maximum 120 (valid for t+00:00 to t+00:20) Note that the maximum seen is copied to the maximum RRA and the average is calculated by averaging the averages. So, you have four RRAs: 5 minutes per row and 20 minutes per row, averages and maxima. RRA0: 5-minute averages: 120,80,100,100 RRA1: 5-minute maxima: 120,80,100,100 RRA2: 20-minute averages: 100 RRA3: 20-minute maxima: 120 If you select the wrong RRA, you are selecting the maximum of the averages and are thus getting 100, not 120. I hope this makes it clear. cheers Alex -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
