Date: Mon, 7 Jul 2014 10:43:00 +0700 From: Victor Sudakov <vas@mpeks.tomsk.su> To: freebsd-questions@freebsd.org Subject: Re: Updating and displaying CMOS clock Message-ID: <20140707034300.GA60208@admin.sibptus.tomsk.ru> In-Reply-To: <53BA0493.1030205@gooch.io> References: <20140706153206.GA46262@admin.sibptus.tomsk.ru> <53B9BC4B.4030609@gooch.io> <20140707021022.GB58025@admin.sibptus.tomsk.ru> <53BA0493.1030205@gooch.io>
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Jesse Gooch wrote: > >>> > >>> What's the command to update the CMOS clock to the time of the kernel > >>> clock? > > > > [dd] > > > >>> > >> > >> To get around this I've started using ntpdate on boot. You can put the > >> following in your /etc/rc.conf: > >> > >> ntpdate_enable="YES" > > > > ntpd_sync_on_start="YES" does the same, but it is not an answer to the > > question, it is a workaround. > > > > Sure, it's a workaround. Why is it so important to set the CMOS clock if > you can just query the current time from a more accurate source on boot? Because there are many scenarios where 1) the network is not yet available on boot (at least at the moment when /etc/rc.d/ntpdate is called); 2) the box has dual boot (e.g. FreeBSD/Windows/DOS whatever) and it would be nice to have an accurate time in the CMOS clock for the alternate OS; 3) ... (others can add their own reasons). > The drift on clocks integrated into computers these days is pretty > terrible AFAIK, which is why NTP is so widespread. If the hardware clock is updated maybe daily, I don't expect any significant drift. -- Victor Sudakov, VAS4-RIPE, VAS47-RIPN sip:sudakov@sibptus.tomsk.ru
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