Updating and displaying CMOS clock

RW rwmaillists at googlemail.com
Mon Jul 7 12:53:37 UTC 2014


On Mon, 7 Jul 2014 13:08:16 +0100
RW wrote:

> On Sun, 6 Jul 2014 22:32:07 +0700
> Victor Sudakov wrote:
> 
> 
> > And no, contrary to popular belief, the correction of the CMOS clock
> > does not happen automatically in FreeBSD even if ntpd is running.
> 
> Are you sure about that? That used to be the case, but I thought it
> was fixed in 10-CURRENT.


I missed this:

On Mon, 7 Jul 2014 17:39:55 +0700
Victor Sudakov wrote:

> I have been told about the machdep.rtc_save_period sysctl, but it
> seems undocumented.


It looks like it has been fixed. I never followed the PR, but the
solution discussed on the mailing list was to update the hardware clock
from the system clock every 30 minutes

$ sysctl -d  machdep.rtc_save_period 
machdep.rtc_save_period: Save system time to RTC with this period (in seconds)

$ sysctl  machdep.rtc_save_period 
machdep.rtc_save_period: 1800



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