From owner-freebsd-questions@FreeBSD.ORG Tue Apr 21 14:20:58 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 648EB106566C for ; Tue, 21 Apr 2009 14:20:58 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: from mail-ew0-f171.google.com (mail-ew0-f171.google.com [209.85.219.171]) by mx1.freebsd.org (Postfix) with ESMTP id BCED18FC13 for ; Tue, 21 Apr 2009 14:20:57 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: by ewy19 with SMTP id 19so2179714ewy.43 for ; Tue, 21 Apr 2009 07:20:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:subject :message-id:in-reply-to:references:x-mailer:mime-version :content-type:content-transfer-encoding; bh=dHZA5GedywBFPCh5bQETbrl8ZFeqt4wxif6XSR77yIE=; b=GBWw/Dm0q2lCykYgAB6TFQDeko0fJyWBeswetOysCGW3hBS2z5XxN+2Pqvkbgp0laK uAzI4KgI2VtopcHGaATT0hODlcMeFo2SdK5dqiR7+kJKqhva5oSJipozoZQqvLDfCVSZ ZU/duZTSNrWU61diPznuZ6cSzsaG0mtBpxnSA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=date:from:to:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type:content-transfer-encoding; b=REx4QjOdoNOsX3Txa2mmEQVgq0OXV6AB7tou0kiNpB3ve8ixfaIjqtg0MOAIA4BoAF eGLuWbFAn8iK4/KpfD5EA6TdeZp824Q3RdQh6fEAqWBpWRD5/R6ixc+Cvvo55brHpK44 4WUVLXNc2TQXWd0yH1+oPgpwQB+JwOuTeyML0= Received: by 10.216.38.68 with SMTP id z46mr608978wea.6.1240323656707; Tue, 21 Apr 2009 07:20:56 -0700 (PDT) Received: from gumby.homeunix.com (bb-87-81-140-128.ukonline.co.uk [87.81.140.128]) by mx.google.com with ESMTPS id 10sm3197074eyd.52.2009.04.21.07.20.55 (version=SSLv3 cipher=RC4-MD5); Tue, 21 Apr 2009 07:20:55 -0700 (PDT) Date: Tue, 21 Apr 2009 15:20:52 +0100 From: RW To: freebsd-questions@freebsd.org Message-ID: <20090421152052.0e6d6916@gumby.homeunix.com> In-Reply-To: <200904211409.09360.mel.flynn+fbsd.questions@mailing.thruhere.net> References: <200904211106.01965.mel.flynn+fbsd.questions@mailing.thruhere.net> <49ED9454.5030100@infracaninophile.co.uk> <200904211409.09360.mel.flynn+fbsd.questions@mailing.thruhere.net> X-Mailer: Claws Mail 3.7.1 (GTK+ 2.16.1; i386-portbld-freebsd7.1) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: Preventing ntpd from adjusting time (backwards) 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: Tue, 21 Apr 2009 14:20:58 -0000 On Tue, 21 Apr 2009 14:09:09 +0200 Mel Flynn wrote: > On Tuesday 21 April 2009 11:39:32 Matthew Seaman wrote: > > * Don't run 'ntpd -g' as the documentation tells you is the > > modern and accepted method. Instead, run 'ntpdate' as a separate > > process and run 'ntpd' without the '-g' flag. > > Hmm, isc sure knows how to abstract something as simple as command > line options into several levels. From the source, -q activates > mode_ntpdate which is one path for time reset. Since not using that, > it's not that path. > > The other codepath, has 4 possibles, 2 of which relating to step-in > and step- out, which I could increase to values that are less likely > to cause a step. Would be worthwhile if there aren't 2 other > possibilities which most likely cause the "step back after reboot" > syndrome: The bottom line though, is that ntpdate_enable=yes solves the problem entirely, since the real problem is not the step, but the fact that it happens in the background, and after a delay. ntpdate may be deprecated, but it's been deprecated for years, and I doubt it will go away until ntpd fully replaces it's functionality. ntpd -gq can replace ntpdate in a crontab, but ntpd -gqn doesn't really replace ntpdate -b in the boot-sequence.