[ntp:questions] Startup transient with missing drift file

Spoon root at localhost.invalid
Mon Apr 9 20:16:33 UTC 2007

Hal Murray wrote:

> What should it look like?  How long should it take to get stable?
> I was expecting ntpd to think for a while, then jump to close to
> the right value, then converge to the final value.  I'd expect
> that to take an hour or so.

(I'm running Linux 2.6.20.x and ntpd 4.2.4p0)

When I start ntpd with no drift file, it remains in state 3 for 15 
minutes, reporting 0 frequency offset, then moves to state 4 and gives a 
close approximation of the current frequency offset.

> What I'm seeing (recent ntp-dev) is that the jump doesn't get
> very close and the converge part takes multiple hours, depending
> upon how far off the jump was.
> Has anybody else watched a startup transient recently?
> I've been looking at a lot of them while chasing a Linux
> glitch that doesn't compute the CPU frequency repeatably.
> What should happen if I start with an explicit drift value
> that is way off?

In my case, it takes hours to slooowly reach the "new" frequency offset.


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