Date: Thu, 09 Nov 2000 19:57:38 -0800 From: Drew Tomlinson <drewt@writeme.com> To: 'Dan Nelson' <dnelson@emsphone.com> Cc: "'FreeBSD Questions (E-mail)'" <freebsd-questions@FreeBSD.ORG> Subject: RE: ntpd "Synchronization Lost" Errors Message-ID: <BA5D0CE1CBB2D411B6AA00A0CC3F02390AF702@ldcmsx01.lc.ca.gov> In-Reply-To: <20001109142516.A22141@dan.emsphone.com>
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> -----Original Message----- > From: Dan Nelson [mailto:dnelson@emsphone.com] > Sent: Thursday, November 09, 2000 12:25 PM > To: Drew Tomlinson > Cc: 'FreeBSD Questions (E-mail)' > Subject: Re: ntpd "Synchronization Lost" Errors > > > In the last episode (Nov 09), Drew Tomlinson said: > > > Yow. an offset of 32 seconds is a whole lot. What is > the contents > > > of /etc/ntp.drift? If it's over 500 or less than -500, ntpd will > > > have a hard time keeping your clock in synch because it drifts too > > > fast. > > > > 145 Blacksheep# cat ntp.drift > > -500.000 > > NTP limits drift to 500 ppm, so that means that your clock is probably > worse than 500. > > > > I'd set up a cron job that fires every hour and runs "cat > > > /etc/ntp.drift >> /var/log/ntp.drift", and check that log after a > > > day or so so see what the trend is. > > > > So is the ntp.drift file recalculated after every update? I haven't > > gotten to cron jobs yet but I guess there's no time like > the present. > > :) > > The drift file is updated once an hour, I believe. > > > I edited my ntp.conf file to point to a different server and > > restarted ntpd. I received the following messages in my log file: > > > > Nov 9 08:59:32 blacksheep ntpd[1546]: ntpd 4.0.99b Mon Nov > 6 00:47:01 PST 2000 (1) > > Nov 9 08:59:32 blacksheep ntpd[1546]: using kernel > phase-lock loop 2040 > > Nov 9 08:59:32 blacksheep ntpd[1546]: frequency > initialized -500.000 from /etc/ntp.drift > > Nov 9 08:59:32 blacksheep ntpd[1546]: using kernel > phase-lock loop 2041 > > > > I don't know exactly what they mean but I didn't get them > before. Now I get > > the following with ntpdc: > > You should get those lines every time ntp is started. > > Another thing you can try is changing your clock source. Add the > following lines to your kernel config file and recompile: > > options CLK_USE_I8254_CALIBRATION > options CLK_USE_TSC_CALIBRATION > > That should calibrate two internal clocks against the CMOS > clock, which > is usually pretty accurate. I've taken your suggestion and recompiled my kernel with the above options. After the first update, my drift is now just 3.954. So it looks like things are working much better now. Thanks again! Drew > -- > Dan Nelson > dnelson@emsphone.com > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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