Preventing ntpd from adjusting time (backwards)

[RW]

On Tue, 21 Apr 2009 14:09:09 +0200
Mel Flynn <mel.flynn+fbsd.questions at mailing.thruhere.net> wrote:

> On Tuesday 21 April 2009 11:39:32 Matthew Seaman wrote:

> >   * Don't run 'ntpd -g' as the documentation tells you is the
> > modern and accepted method.  Instead, run 'ntpdate' as a separate
> > process and run 'ntpd' without the '-g' flag.
> 
> Hmm, isc sure knows how to abstract something as simple as command
> line options into several levels. From the source, -q activates
> mode_ntpdate which is one path for time reset. Since not using that,
> it's not that path.
> 
> The other codepath, has 4 possibles, 2 of which relating to step-in
> and step- out, which I could increase to values that are less likely
> to cause a step. Would be worthwhile if there aren't 2 other
> possibilities which most likely cause the "step back after reboot"
> syndrome:

The bottom line though, is that ntpdate_enable=yes solves the problem
entirely, since the real problem is not the step, but the fact that it
happens in the background, and after a delay.

ntpdate may be deprecated, but it's been deprecated for years, and I
doubt it will go away until ntpd fully replaces it's functionality.
ntpd -gq can replace ntpdate in a crontab, but ntpd -gqn doesn't really
replace ntpdate -b in the boot-sequence.