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

[Juergen Daubert]

On Sat, Jun 06, 2009 at 04:17:39PM -0400, Harlan Stenn wrote:
> Juergen Daubert wrote:
> > On Sat, Jun 06, 2009 at 08:19:14PM +0200, Arno Wald wrote:
> > > I am running dovecot on a PC (a workstation) to have a mail client  
> > > independent storage for my mails. Now I would like to have the system  
> > > clock set correctly by using ntpd or ntpdate (using debian/sid).
> > >
> > > The problem is, that the PC is not online at boot time, but is set  
> > > online on demand manually using "pon" to start the pppd later. So ntpd  
> > > cannot sync the time on boot time before dovecot gets started.
> > 
> > Chrony is what you are looking for, see http://chrony.sunsite.dk/
> 
> 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.

- 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.


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