[plug] Slow System Clock

[William Kenworthy]

Tim, have a read of the ntp docs at ntp.org on why ntpdate is not a good
idea, and why it is deprecated in favour of ntpd.  PC time is a very
complex thing: i.e., the kernel keeps track of perceived drift.  If this
gets out of spec, you start to see time gain/loss like you have -
ntpdate just sets the time, it wont fix drift problems like ntpd can.  

Also, some applications on some hardware cause timeloss because of the
way they read the time information (i.e., batter status apps on dell
hardware are one I personnaly came a cropper on.)  The last examples of
time problems occurred on 2.6.10 and earlier kernels (major jitter)

A possible fix: delete /etc/adjtime, /etc/ntp.drift (if it exists) while
all ntp like programs are not running.  The run ntpd pointing to some
local and stable servers in order for the correct drift correction data
to be set.  If correctly setup, this will write the drift correction
factor.

Lastly this does not always work - my laptop still loses time, I think
because of suspend/resume issues, but its not serious enough to lose
sleep over, and appears to be correcting itself slowly since I have
moved to sofware suspend2 rather than apm suspend to ram.

BillK



On Sun, 2005-04-10 at 11:23 +0800, Timothy White wrote:
> My Nice new AMD 64 3000+ appears to be loosing time. I did a ntpdate to
> update the clock last night and just did it again and it need to adjust
> it by more than 250 seconds. I also did an ntpdate yesterday afternoon
> and between that update and last night it had lost about 180 seconds.
> The machine has been running the whole time without reboots or the like
> and is running a 2.6.10 kernel. I can't think of anything that would be
> causing it to lose time except maybe some 'standby' feature or something
> but I know of none.
> 
> Thanks
> 
> Tim
> 
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-- 
William Kenworthy <billk at iinet.net.au>
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