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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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