[ntp:questions] Re: why is it so important that your servers all have the same notion of time?

Richard B. Gilbert rgilbert88 at comcast.net
Sun Dec 12 18:54:52 UTC 2004

Folkert van Heusden wrote:

>The subject says it all.
>Where I work (an academic hospital in the netherlands), we have 4
>Now I would like to introduce a fith timeserver but that one with a DCF77-
>receiver connected to it so that we've always a real good notion of time.
>I would say that is very important but I really can't give any good reasons
>for that. Very unfortunate.
>So my question is: why should we?
>Folkert van Heusden
>|UNIX admin? Then give MultiTail (http://vanheusden.com/multitail/)|
>|a try, it brings monitoring logfiles to a different level! See    |
>|http://vanheusden.com/multitail/features.html for a feature list. |
>+------------------------------------------= www.unixsoftware.nl =-+
There are, I believe, two issues: correctness and stability.  
Correctness simply means that the time can be meaningfully compared and 
may be important for legal reasons.  Stability means that the server is 
"ticking" at a constant rate; it may not be exactly correct but it is 
predictable.  Stability is important because it is much easier to 
synchronize closely with a stable source.

Adding a server synchronized by DCF77 could provide a time source that 
is both more stable and more accurate than a server getting time over a 
wide area network.  VLF propagation can be more predictable than either 
HF propagation or a network. 

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