Re: How to use ntp/ntpdate to fix my clock
On Sat, 29 Jan 2000, Eric Gillespie, Jr. wrote:
> On Sat, Jan 29, 2000 at 08:46:07AM -0200,
> Henrique M Holschuh <hmh+debianml@rcm.org.br> wrote:
> > Edit /etc/init.d/ntpdate and add the server(s) you selected. Remove
> > hwcloch --adjust calls in /etc/init.d/hwclock.sh because it will bite you
> > sooner or later.
>
> Just out of curiosity, what kind of problem does hwclock cause for ntp?
Ohboy... There's a thread in devel right now about it, and I should be
sending a rather big post about the issue in a few minutes, and might even
fill some bug reports. I'll bcc: you for that post, and you can read the
thread in the devel archives if you want.
Basically, ntp + hwclock --adjust may corrupt the system time during boot,
and ntp without ntpdate (or if ntpdate fails to set the clock) may refuse to
start because of that (ntp does not start if the system clock is way too far
from the correct time).
Also, hwclock --systohc disables the 11 minute update mode in the kernel,
and ntp may stop updating the kernel clock because of that.
hwclock --hctosys makes no sense if you're running ntp, as ntp keeps the
system time disciplied with much more precision than hwclock ever could.
hwclock also gets completely confused if the RTC is set by anything other
than hwclock --set (ntp does this every 11 minutes :-) ), and miscalculate
the data it uses for --adjust.
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
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