From owner-freebsd-questions@FreeBSD.ORG Mon May 7 23:55:31 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 5483616A403 for ; Mon, 7 May 2007 23:55:31 +0000 (UTC) (envelope-from jdow@earthlink.net) Received: from elasmtp-banded.atl.sa.earthlink.net (elasmtp-banded.atl.sa.earthlink.net [209.86.89.70]) by mx1.freebsd.org (Postfix) with ESMTP id 0E14F13C457 for ; Mon, 7 May 2007 23:55:31 +0000 (UTC) (envelope-from jdow@earthlink.net) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=DjcWSeLywhpMN2dEPjpwiYv08tXk0ITVMTPNv09RL/VWdzjBVwzDeqYGWYIZIjcS; h=Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-ELNK-Trace:X-Originating-IP; Received: from [208.127.11.96] (helo=wednesday) by elasmtp-banded.atl.sa.earthlink.net with asmtp (Exim 4.34) id 1HlD3A-0006sh-C8 for freebsd-questions@freebsd.org; Mon, 07 May 2007 19:55:28 -0400 Message-ID: <00a301c79103$304a17c0$0225a8c0@wednesday> From: "jdow" To: References: <20070503014137.I3544@duane.dbq.yournetplus.com><20070503015723.S3544@duane.dbq.yournetplus.com><4639FAB6.9050701@mac.com><20070504171053.41eddb6a@gumby.homeunix.com><7967B2A8-3FF5-46AD-AFEA-9EE5C680A414@mac.com><20070507230246.198b6608@gumby.homeunix.com.> Date: Mon, 7 May 2007 16:55:27 -0700 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-ELNK-Trace: bb89ecdb26a8f9f24d2b10475b571120255be5e67749b388117d63dbde98688d8f4d5db824d3dbdc350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 208.127.11.96 Subject: Re: Time Synchronizing Between Two Servers X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 May 2007 23:55:31 -0000 From: "Jeffrey Goldberg" > On May 7, 2007, at 5:02 PM, RW wrote: > >> If the time error is zeroed by ntpdate, and there's a drift-file, I >> don't see that the actual drift value makes much difference. I suspect >> that any quartz clock is overkill. > > As someone already mentioned, drift data doesn't really solve the > problem if the amount of drift varies (often with temperature, and > sometimes dramatically with sleep). The clock on my wife's G5 iMac > seems to be erratic, but I haven't (and won't) bother to investigate > further. If her system is up to 2 seconds off for a bit after waking > from sleep, so be it. (If I ever start using kerberos around the > house, I will have to address that.) > > If a machine is up for months, ntpdate may have been run in the > distant past, so you can still a fair amount of error. > > ntpd is really a very light weight thing. When things are ticking > over nicely, it may make just one query every few hours and still > keep very good time. > > Also, if you have a server facing the Internet, you may wish to run a > public NTP service on it and contribute it to pool.ntp.org, see > > http://www.pool.ntp.org/join.html > > for info. Real NTP goes up to 1024 seconds between polls in my experience. (And it NEVER jam sets when it is working correctly. Of course, with MS crap this is not necessarily true.) {^_^} Joanne