[ntp:questions] [SOLVED] Default config on Ubuntu doesn't work as client
david at ex.djwhome.demon.co.uk.invalid
Tue Mar 11 07:30:20 UTC 2008
Michael B Allen wrote:
> The following config works:
> driftfile /var/lib/ntp/ntp.drift
> server 192.168.2.15 iburst
> The clock was sync'd in a matter of seconds.
> I kinda figured it would work since I have other servers that use it
> and I've asked about this on this list before and was told that the
> above was the minimum client config. I was just intrigued that Ubuntu
It's not minimum; it includes some, but not all, of the optional things
that are considered best current practice (it doesn't contain 4 servers,
which is the other common BCP requirement).
Given that your drift rate is 6666 ppm and ntpd needs it to be somewhat
less than 500ppm, I suspect you are getting a continuous sequence of
steps and you just happened to look after a step (and iburst is allowing
it to actually get a time measurement fast enough that it does exceed
128ms before the time is measured.
I don't know how VMWare handles the TSC, but unless it handles it in a
away intended for real time measurement, rather than CPU usage
measurement the calibration may be run at a time that doesn't match
average conditions. If that theory is correct, you need to disable TSC
as a time source.
> could ship with a default config that didn't actually work and wanted to
> see if someone could pinpoint why. I have a feeling there are a lot of
> Ubuntu users out there who think their clocks are syncing when in fact
> they're not.
> Thanks for the entertainment,
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