Date: Fri, 14 Apr 2006 12:07:13 -0400 From: wc_fbsd@xxiii.com To: freebsd@dfwlp.com,freebsd-questions@freebsd.org Subject: Re: Proper Method of Time Sync? Message-ID: <6.2.3.4.2.20060414115321.02e7f110@mailsvr.xxiii.com> In-Reply-To: <5507.208.11.134.3.1145029242.squirrel@mail.dfwlp.com> References: <5507.208.11.134.3.1145029242.squirrel@mail.dfwlp.com>
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At 11:40 AM 4/14/2006, Jonathan Horne wrote: >i have read about 2 methods to sync the time on a freebsd box. >...i have a workstation and a server, which i originally did method >1 on, but soon enough, time drifted quite a bit. so i switched it >to the 2nd method, and they appear to be sync'd perfectly. a third >box i set up, i did only method 2, and this one did not stay synced >at all. after i manually ran 'ntpdate -v -b us.pool.ntp.org', this >box straightend up. First off, ntpdate is obsolete, and will be retired "sometime in the future". Its functionality has been incorporated into ntpd. I think your problem is a limit in ntpd that's enabled by default. There is a limit on how large a correction ntpd will make at one time, even at boot up. ntpdate isn't that picky and always just syncs, even if the offset is large. Try some rtfmp on ntpd, ntpdate and ntpd.conf. I run ntpd on one server, with a flag (-g) set to always sync, eg: rc.conf: ntpd_sync_on_start="YES" # Sync time on ntpd startup, even if offset is high ntpd_flags="-A -p /var/run/ntpd.pid" And ntp.conf: server rolex.usg.edu driftfile /etc/ntp.drift logfile /var/log/ntpd.log restrict 208.62.177.32 mask 255.255.255.224 nomodify notrap My other servers and desktops are similarly configured, but sync off the first server. Be sure to specify the driftfile; ntpd will "learn" how fast or slow your clock is and record it, so it can apply corrections when/if an internet connection isn't up. Be sure the file exists and has some number. You can initialize with: echo "0" > /var//db/ntp.drift
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