In <AANLkTi=UHCRZ=zYJWktNTCdMbTonh92W5NvL2JNzgpF2 at mail.gmail.com> Steve Holmes <sholmes42 at mac.com> writes:
It's because at longer history the values are averaged over longer time intervals.
It would seem that is what is happening, but is that appropriate for things like CPU values? 100% of the CPU is constant over time. And it looks like when he takes a certain path to zoom in, he sees expected values.
When you look at a graph, rrdtool will automatically decide which of the 4 datasets it is going to use - the 48-hour set, the 12-day set etc. - based on what timeperiod you are looking at. So if you start with the 12-day set but zoom into a period within the past 48-hours, then it will automatically switch from using the 12-day averaged set to the higher-precision 48-hour set - that's why you then see the peak just like you do on the 48-hour graph.
Wait a couple of days, and when you zoom in on the same peak, it won't be as high as it was today.
Regards, Henrik