Date: Thu, 13 Mar 2014 11:01:14 -0700 From: Charles Swiger <cswiger@mac.com> To: mexas@bris.ac.uk Cc: FreeBSD - <freebsd-questions@freebsd.org> Subject: Re: ntp frequent time resets - battery dead? Message-ID: <F146857D-4705-4DDE-8C85-F712D311BEF0@mac.com> In-Reply-To: <201403121926.s2CJQXbQ078112@mech-cluster241.men.bris.ac.uk> References: <201403121926.s2CJQXbQ078112@mech-cluster241.men.bris.ac.uk>
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Hi-- On Mar 12, 2014, at 12:26 PM, Anton Shterenlikht <mexas@bris.ac.uk> = wrote: >> Yes, it looks to be about ~1 second per hour. That's 1:1000 ratio, >> which is getting close to the typical kernel limit on adjtime(). >>=20 >> Tweaking the step threshold might help. Or look into tickadj / = ntptime. >=20 > Sorry, I don't understand this. > Please elaborate. OK. ntpd has two ways of adjusting the clock; either it gradually slews = the time via adjtime() or it jumps the clock via settimeofday() and logs the = "time reset" lines you've noted. Which method is chosen is based upon the step threshold, which defaults = to 128 ms (aka .128 seconds). Increasing the step threshold will have ntpd try to = slew the clock even for the larger corrections your case seems to need. Regards, --=20 -Chuck
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