Clock issues

[Bob Chiodini]

On Wed, 2005-11-09 at 10:40 -0800, Brian D. McGrew wrote:
> Running a Dell PE850 with FC4 installed.  I used rdate -s to set the
> clock and the time is correct.  I even have it in the crontab tab.
> 
> When the machine reboots, the clock is wrong, way wrong by anywhere from
> 6 to 12 hours.  How do I get the clock to sync up at reboot time?
> 
> -brian
> 
> Brian D. McGrew { brian at visionpro.com || brian at doubledimension.com }
> --
> > Those of you who think you know it all,
>   really annoy those of us who do! 
> 
Brian,

Are you cleanly rebooting the system?

/etc/init.d/halt contains code to set the hardware clock to the system
(software) clock.  Unless the motherboard battery is failing, or the
system was not properly shutdown/rebooted the H/W clock should not drift
that much.

Running rdate from cron only sets the system clock, not the H/W clock.
You should also run hwclock --systohc in the same cron job.

As suggested by Yonas and Alexander, NTP is another solution, but it
will not correct the H/W clock by itself.  You still must insure that
hwclock runs, either periodically, or at shutdown.

What is the BIOS time immediately after shutting down?


Bob...