Threshold value measurements

[andy]

Hi,

Just setting up thold and I'm struggling to work out what the units are when setting the upper and lower values on ethernet interfaces. Memory and CPU work fine but any interfaces seem to report weird values based on what the graphs say they are doing.

The 601800.9041 thold reports in this attachment does not seem to be bits, bytes, kilobits, kilobytes or any other kind of bacndwidth measurement that would equal 5M (both of the captures were taken at the same time).

That particular link is a 10M WAN ethernet interface which I want to alert at 7M, but it was emailing me with attached graphs showing 1M in / 3M out alerting that it had gone past the threshold. Can someone please let me know what I'm doing wrong?

TIA,
andy

[andy]

I get the feeling that thold works on bytes for interfaces as well as memory and hdd space as opposed to bits?

[cigamit]

Thold just uses the exact value stored in the RRD file. What that value is depends on the script/graph you are using. It may be bits or it may be bytes.

[user071310]

The values are not matching.

Anyone have any suggestions to resolve this?

[TheHack]

My understanding is that the interface in and out MIB is returning bytes per sec. and not in bits per sec. The graphs however do a CDEF (turn bytes into bits) to show the usually bandwidth graphs in bps.
You may add the same CDEF to the Threshold alert and thus compare also bps instead of bytes per sec.

Alternatively you may check out the thread on:
http://forums.cacti.net/viewtopic.php?t=29050

If you calculate the thold value times 8, you get almost the same as in the graph (you need to check if you have put in "LAST" or "AVERAGE" in the legend field for the current value since RRD may do some calculations as well.