Re: Kernel msg in linux rh 6.2

[Ulrich Windl]

The following message is a courtesy copy of an article
that has been posted to comp.protocols.time.ntp as well.

"Jan Rockstedt" <[e-mail]> writes:

> Hi !
> 
> I have a kernel msg on my console.
> 
> Jun 22 10:35:07 linux kernel: set_rtc_mmss: can't update from 54 to 5
> Jun 22 10:36:08 linux kernel: set_rtc_mmss: can't update from 54 to 6
> Jun 22 10:37:09 linux kernel: set_rtc_mmss: can't update from 54 to 7

OK, as this message was introduced by myself, I'd like to explain:

There's a long-standing bug when updating the CMOS clock, as the
kernel just updates minutes and seconds to avoid timezone problems
(the original author must have thought). However if you are correcting
your time around the start of the hour (like from x:54:yy to z:05:yy),
you must change the hour, or other wise you'll lose or gain an hour.

Imagine it's 14:54:06 and the correct time is 15:05:37. When updating
minutes and seconds, you'll get 14:05:37, and not 15:05:37. That's
what the message is about.

The correct fix is either to update the cmos clock with the correct
time, or you'll wait several minutes until the window is better (in
the example in about 5 minutes), or you use PPSkit-0.9.x that will
correctly do the CMOS clock updates.

> 
> I am using xntpd for sync my clock.
> 
> What is this ?

A candidate for the NTP FAQ I guess ;-)

Regards,
Ulrich

> 
> 
> Regards Jan Rockstedt
> 
> --
> 
> person: Jan Rockstedt
> address: Datarutin Media AB
> address: Box 125
> address: S-201 21 Malmo
> address: Sweden
> phone: [phone]
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