nate wrote:
Neil Aggarwal wrote:
I just need something that gives me a usage graph at daily, weekly, and monthly intervals with a 95% line.
Don't use RRD for billing 95% it will not be accurate as RRD averages values over time. I use rtg (not mrtg, but rtg) together with SNMP to get accurate 95% readings at the interface/port level.
sflow is also a sampling mechanism, but it is pretty accurate depending on the interval, you can see this site for accuracy on sflow:
http://www.sflow.org/packetSamplingBasics/index.htm
If your just using rrd for casual monitoring, no problem but if your using it for billing at 95% then be careful.
RRD stores a certain number of samples at their collected values, then as they age, averages them into larger and larger time values per sample, with the numbers of each set being configurable. If you keep the raw samples for the time span of the calculation you should get accurate values.