From owner-freebsd-questions@FreeBSD.ORG Tue Apr 22 12:44:16 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 59FB837B401 for ; Tue, 22 Apr 2003 12:44:16 -0700 (PDT) Received: from grumpy.dyndns.org (user-24-214-34-52.knology.net [24.214.34.52]) by mx1.FreeBSD.org (Postfix) with ESMTP id 81E1143F75 for ; Tue, 22 Apr 2003 12:44:15 -0700 (PDT) (envelope-from dkelly@grumpy.dyndns.org) Received: from grumpy.dyndns.org (localhost [127.0.0.1]) by grumpy.dyndns.org (8.12.9/8.12.9) with ESMTP id h3MJiE14013896; Tue, 22 Apr 2003 14:44:14 -0500 (CDT) (envelope-from dkelly@grumpy.dyndns.org) Received: (from dkelly@localhost) by grumpy.dyndns.org (8.12.9/8.12.9/Submit) id h3MJiEqq013895; Tue, 22 Apr 2003 14:44:14 -0500 (CDT) Date: Tue, 22 Apr 2003 14:44:13 -0500 From: David Kelly To: Charles Swiger Message-ID: <20030422194413.GC13774@grumpy.dyndns.org> References: <20030422184554.GA13432@grumpy.dyndns.org> <4B518202-74F8-11D7-BCB7-003065ABFD92@mac.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B518202-74F8-11D7-BCB7-003065ABFD92@mac.com> User-Agent: Mutt/1.4.1i cc: FreeBSD-Questions@freebsd.org Subject: Re: Accurate time without a network connection? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Apr 2003 19:44:16 -0000 On Tue, Apr 22, 2003 at 03:26:19PM -0400, Charles Swiger wrote: > > Ok. If you run NTPD with only the local hardware clock for a > reference, wait for a week, and then see how the intrinsic drift of the > hardware compares with "real time" (using your watch or some other time > source), you can adjust /etc/ntp.drift by hand. This isn't going to be > perfect, but it's going to be much more accurate than doing nothing. Good. But already tried that. The situation is multiple systems have to run with something near the same time, but no bidirectional contact. And need to operate for years. Letting ntpd tune itself and then free run works much better than the system clock alone but only good for weeks, not months. As for exactly what time the systems have, it doesn't much matter as long as they all have the same time. -- David Kelly N4HHE, dkelly@hiwaay.net ===================================================================== The human mind ordinarily operates at only ten percent of its capacity -- the rest is overhead for the operating system.