I'm trying to get cacti to measure my CPU, iowait, and bandwidth. So far I can get the bandwidth and iowait to match perfectly with linode. But my CPU measurement is way off. I'm pretty sure linode's is correct so my question is does anyone know what template they are using? I've tried various (including ucd/net - CPU Usage below) but no cigar.

Linode:




Cacti:

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My usual first guess is always scale mismatch: the Linode CPU graph ranges from 0 to 400% while some tools always scale it to 0-100%, but the graphs don't differ by a factor of four so that might not be it.

I might try running a single CPU-bound thread for awhile (~30 minutes or so), spinning one CPU at ~100%... throwing a big, constant load at both graphs simultaneously should establish what sort of error it is.

Just out of curiosity, which kernel/version are you running? Ultimately, the number cacti is reporting comes from the kernel, so perhaps there's a known (or at least reproducible) difference between that kernel version and whatever the hypervisor-dowsing expedition feeds Linode's graphs.

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Thanks, running one core at 100% showed me which cpu graphs were incorrect. I used a different 4 core template (Host MIB) and now it matches linodes.

Care to share your results so if someone else has the same problem in the future?

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Travis

I used verbatim the 4 cpu template described here:

http://www.goldfisch.at/knowwiki/howtos ... u_graphing

pictutorial here:

http://www.powercram.com/2010/01/multi- ... cacti.html