[mrtg] effects of changing interval on existing databases

[rihad]

Hi there,

What will the effects of changing the Interval setting have on existing 
databases? On new databases? All mrtg-reference* says is:

  If you change the interval later, all existing databases will remain at
  the resolution they were initially created with.

Can you provide an example of what exactly this means? Here come the 
first 5 lines of an example logfile we have:

1225174811 231267006 1861787286
1225174811 591 76 591 76
1225174510 2502 411 2502 411
1225174500 2528 429 3291 953
1225174200 3235 935 3291 953

(As you may have guessed we're using an older mrtg 2.13.2 which cannot 
be easily upgraded for various reasons).

As you can see the Interval above is 5. If we change it to 10, how will 
the logfile above change? At what resolution will new samples be added 
to it? How will a new logfile (created after the change) look? I assume 
logfiles created before and after the setting change will look and 
behave differently? It's cheaper to ask here than to set up a sandbox 
just to find out :)

Thanks.