[CentOS] NTP and hardware clock

Wed Oct 11 17:41:18 UTC 2006
Dag Wieers <dag at wieers.com>

On Wed, 11 Oct 2006, Kirk Bocek wrote:

> Dag Wieers wrote:
> > I fail to see how that is relevant, since the local clock is wrong after a 
> > reboot without network (so I rather not want to use it as a source :)) and 
> > ntpd is not even started because ntpdate fails.
> > 
> > But yes, I do have something like that (stratum 13 though).
> I somehow thought that ntpdate might be trying to access an unavailable time
> source. With these lines, you always have a time source available, even if it
> is inaccurate.

The whole point of ntpdate is to synchronize the local clock with another 
source (ie. not the local clock).

And I guess the main reason why they do not start ntpd if ntpdate fails, 
is because they have to protect other ntp clients from being poisoned by 
a wrong system clock upstream (because its source is unavailable).

So maybe using ntpdate from cron is better than using ntpd. If only there 
was some infrastructure so configuring ntpdate would be done in a 
standardized way.

Maybe that would be a nice feature request for Red Hat. Add a cron-job 
that works if some /etc/sysconfig/ stuff is available.

Kind regards,
--   dag wieers,  dag at wieers.com,  http://dag.wieers.com/   --
[all I want is a warm bed and a kind word and unlimited power]