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Performance graphs over time

Posted: Thu Jun 14, 2012 11:41 am
by hhlodge
I am looking at the CPU usage for a Linux host gathered via SNMP (check_xi_service_snmp_linux_load). If I look at the last 24 hours, week and month, they all have different MAX values. Shouldn't that be the same for each of those periods. i.e. why doesn't yesterday's 97% peak also show as the peak for the last week and month? Is there a problem here or am I misunderstanding something fundamental?
CPU-24hr.png
CPU-week.png
CPU-month.png

Re: Performance graphs over time

Posted: Thu Jun 14, 2012 12:44 pm
by mguthrie
To my knowledge, rrdtool will extrapolate data between point, and depending on what timeframe you select, the resolution of data points will be different.

The rrdtool doc site covers data resolution in more detail:
http://oss.oetiker.ch/rrdtool/doc/rrdfe ... N_INTERVAL