[ntp:questions] Re: "ntpd" and hwclock
Richard B. Gilbert
rgilbert88 at comcast.net
Tue Oct 4 19:16:40 UTC 2005
Ulrich Windl wrote:
>mike <michael.no.spam.cook at wanadoo.fr> writes:
>>>My question does ntpd at any point changes the hardware clock ? If not then
>>>who and when it is
>> my linux (mandrake) also syncs the hardware clock at shutdown. most
>>others will probably do so I guess. So that last delta into the 11 min update
>>is taken care of aswell.
>IMHO the correct time to update the CMOS is when the system time changed, not
>when the system goes down. For SUSE Linux and the RTC running localtime (not
>UTC), a single-user-boot followed by a reboot has always messed up the system
>time. For mandrake you may be more lucky...
I'm inclined to agree! Setting the CMOS clock, or equivalent in other
architectures, only at system shutdown ignores the probability that the
system will not do a clean shutdown. The kernel might panic, the power
might fail, and then you boot up with your clock off by 37 minutes!
All right, I exagerate. A little! But if you are going to use the CMOS
clock to set the system clock when you boot, it makes a great deal of
sense to keep it up to date.
I think it makes more sense to use ntpd or ntpdate to set the clock when
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