From owner-freebsd-questions@FreeBSD.ORG Mon May 7 23:35:16 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 59B9B16A407 for ; Mon, 7 May 2007 23:35:16 +0000 (UTC) (envelope-from jeffrey@goldmark.org) Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by mx1.freebsd.org (Postfix) with ESMTP id 2A63913C45D for ; Mon, 7 May 2007 23:35:15 +0000 (UTC) (envelope-from jeffrey@goldmark.org) Received: from compute1.internal (compute1.internal [10.202.2.41]) by out1.messagingengine.com (Postfix) with ESMTP id 2F0E621F743; Mon, 7 May 2007 19:36:21 -0400 (EDT) Received: from heartbeat1.messagingengine.com ([10.202.2.160]) by compute1.internal (MEProxy); Mon, 07 May 2007 19:35:16 -0400 X-Sasl-enc: SrXldv3oPq6cCnRqCh6BdEktlgZTgw66+W9gGU4c16xU 1178580916 Received: from [10.1.10.136] (n114.ewd.goldmark.org [72.64.118.114]) by mail.messagingengine.com (Postfix) with ESMTP id 1FDE02A96B; Mon, 7 May 2007 19:35:16 -0400 (EDT) In-Reply-To: <20070507230246.198b6608@gumby.homeunix.com.> 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.> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Jeffrey Goldberg Date: Mon, 7 May 2007 18:35:13 -0500 To: RW X-Mailer: Apple Mail (2.752.2) Cc: freebsd-questions@freebsd.org 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 23:35:16 -0000 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. -j -- Jeffrey Goldberg http://www.goldmark.org/jeff/