[mrtg] Re: how can I schedule <5 minute intervals?

[Alex van den Bogaerdt]

Alexander Fichman wrote:
> 
> You mean leave the MRTG config file setting on 5 minutes and just run MRTG
> in less than 5 minute intervals?
> 

Yup.

You won't get better granularity of the data but you are able to collect
more data.

When possible, use 64-bit counters.  AFAIK this is not yet wide spread.
They are:
ifHCInOctets  (1.3.6.1.2.1.31.1.1.1.6)
ifHCOutOctets (1.3.6.1.2.1.31.1.1.1.10)

If you have to use 32-bit counters, you may run into problems. One of them
is the maximum rate that you can monitor.  The maximum rate for a 32-bit
counter can be calculated. The maximum value is 2^32-1 == 4294967295.

Sampled every x minutes        maximum rate
(x*60 seconds)             in bps        in bps
1    (60)                 71,582,788   572,662,304
2   (120)                 35,791,394   286,331,152
3   (180)                 23,860,929   190,887,432
4   (240)                 17,895,697   143,165,576
5   (300)                 14,316,557   114,532,456

Other problems will occur, for instance the counter-wrap problem where
MRTG uses the previous value and not the recently collected counter value.
Also, when calling MRTG more often, chances are that you run into
performance problems.  This is why I recommend to use RRDtool.

Regards,
-- 
   __________________________________________________________________
 / alex at slot.hollandcasino.nl                  alex at ergens.op.het.net \
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