[Dovecot] dovecot and ntp: Fatal: Time just moved backwards

Juergen Daubert jue at jue.li
Sun Jun 7 00:26:47 EEST 2009


On Sat, Jun 06, 2009 at 05:06:50PM -0400, Harlan Stenn wrote:
> Juergen wrote:
> > > How will chrony help here if the PC is not online at boot time?
> > 
> > >From http://chrony.sunsite.dk/guide/chrony.html
> > 
> > - chronyd can perform usefully in an environment where access to the time
> >   reference is intermittent. chronyd estimates both the current time
> >   offset and the rate at which the computer's clock gains or loses time,
> >   and can use that rate estimate to trim the clock after the reference
> >   disappears.
> 
> Doesn't apply to the use case.  This is *before* the PC goes online.
> 
> > - chronyd provides support to work out the gain or loss rate of the
> >   `real-time clock', i.e. the clock that maintains the time when the
> >   computer is turned off. It can use this data when the system boots to
> >   set the system time from a corrected version of the real-time clock.
> 
> There is no corrected version of the real-time clock before the PC goes
> online.

I'd suggest to read chrony's manual. Chrony stores the reference values
collected while running online for further use after reboot, even if we
have no online connection at that point.
Of course, this doesn't work if you never have synced with an NTP server.


-- 
Juergen Daubert  |  mailto:jue at jue.li  
Korb, Germany    |  http://jue.li/crux



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