[ntp:questions] Can a clock drift be too big for ntpd?

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Fri Oct 19 02:26:07 UTC 2007

>It seems as if ntpd can't keep its clock syncronized.  It's
>drifting about 6-10 minutes per day, well over the 500 ppm limit.

>After reading some of the posts on this newsgroup, I have come
>to realize that debugging ntp problems can be quite complex.
>Before I launch into a detailed search, I would like to clarify
>one question.  Is it possible for the clock frequency to be so 
>far off that ntpd just can't get it under control?

6 min per day is 4000 ppm.  NTP can't handle more than 500 ppm.

>So, does this look like a hardware problem?

It's a problem.  It may not be hardware.

Do you have any other similar machines?

Are you missing interrupts?  (say because some strange IO
device eats up a lot of CPU processing its interrupts)

These are my opinions, not necessarily my employer's.  I hate spam.

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