[rrd-users] Questions about effective database parameters

Steve Shipway s.shipway at auckland.ac.nz
Thu Dec 23 06:08:22 CET 2010

Oops, I think I gave some bad advice just now and stated the XFF definition backwards.  From the manual:

"xff The xfiles factor defines what part of a consolidation interval may be made up from *UNKNOWN* data while the consolidated value is still regarded as known. It is given as the ratio of allowed *UNKNOWN* PDPs to the number of PDPs in the interval. Thus, it ranges from 0 to 1 (exclusive)."

So it is as Alex said (not how I said!) and you need to get your XFF as close to 1 as you can without it actually being 1 (rather than as close to 0 like I said).

Sorry for any confusion, I should have checked the docs first!


Steve Shipway
University of Auckland ITS
UNIX Systems Design Lead
s.shipway at auckland.ac.nz
Ph: +64 9 373 7599 ext 86487

From: rrd-users-bounces+s.shipway=auckland.ac.nz at lists.oetiker.ch [rrd-users-bounces+s.shipway=auckland.ac.nz at lists.oetiker.ch] on behalf of Alex van den Bogaerdt [alex at vandenbogaerdt.nl]
Sent: Thursday, 23 December 2010 7:02 a.m.
To: rrd-users at lists.oetiker.ch
Cc: "."@vandenbogaerdt.nl
Subject: Re: [rrd-users] Questions about effective database parameters

Any average that contains some unknown data is weird, after
all you cannot determine the average of 1,1,1,1,unknown,1,1,1.
The X-File Factor (xff) is the amount of weirdness that is allowed.
Higher number means more weirdness allowed. 0<=xff<1.

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