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Re: ntp and updating the bios clock by the kernel every 11 minutes.
> On Sun, 30 Jan 2000, Shaul Karl wrote:
>
> > As far as I know new kernels does not write the correct time to the bios clock
> > every 11 min even if the system has a good time reference (ntp or such). This
> > is contrary to what older kernels used to do.
>
> I have never heard of a kernel voluntarily updating the hardware clock,
> or anyything at a weird 11 minute interval. I do however set on some
> wild-clocked old mobos a cron job to write the HWclock once an hour or
> once a day. however if you have NTP synched and a drift file updated by
> xntpd, then you don't even need to do that.
>
The following is from Debian-Users (sent by Henrique M Holschuh
<hmh+debianml@rcm.org.br>):
> > Also, hwclock --systohc disables the 11 minute update mode in the kernel,
> > and ntp may stop updating the kernel clock because of that.
>
> Are you sure? I believe that updating the hw clock every 11min is not done
> with newer kernels.
Yes, I just tested and my 2.2.14 has (a working) 11 minute sync mode all
right (I have no idea about 2.3.x). But it is rather quirky...
I didn't test if hwclock does disable 11 minutes mode, but the man page says
it does.
--
shaulk@israsrv.net.il
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