[ntp:questions] Automatic time synchronization of local hw clock.

Harlan Stenn stenn at ntp.org
Mon Apr 14 10:01:04 UTC 2014

Mimiko writes:
> On 14.04.2014 11:47, Harlan Stenn wrote:
> > So in general, ntpd is running on the box?
> Yes, its running as a service. Its acting as a time server very well for 
> a year.
> > What does ntpd talk to during the months it takes for the time to drift
> > away by 30-60 seconds?
> No logs about this drift of time in ntpd log file. Problem appear only 
> when restarting service (or during system restart).
> >
> > On some operating systems NTP will set the BIOS clock.  I believe this
> > happens once an hour.
> >
> > But not all OSes have this capability, and many BIOS clocks are pretty
> > bad.  So it is not something that can be effectively used very often.
> This is the problem. It's not correcting the BIOS clock. ntpd -q does 
> correct it.

I would expect ntpd -q to correct the system clock, not the BIOS clock.

> This is the command line which starts ntpd as service:
> /srv/ntpd/bin/ntpd -p /var/run/ntpd.pid -g -l /srv/ntpd/log/ntpd.log -s 
> /srv/ntpd/log/ntpstats/ -c /srv/ntpd/etc/ntpd.conf -u

OK, thanks - that looks good.

You might want to consider running a cron job from time to time to set
the BIOS clock from the system clockc, if ntpd is not updating the BIOS
clock for you.


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