From owner-freebsd-questions@FreeBSD.ORG Sat Mar 13 19:08:53 2010 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 0E3E9106566C for ; Sat, 13 Mar 2010 19:08:53 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: from mail-bw0-f216.google.com (mail-bw0-f216.google.com [209.85.218.216]) by mx1.freebsd.org (Postfix) with ESMTP id 8AC5A8FC0C for ; Sat, 13 Mar 2010 19:08:51 +0000 (UTC) Received: by bwz8 with SMTP id 8so1913497bwz.3 for ; Sat, 13 Mar 2010 11:08:51 -0800 (PST) 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=xFPUJKfNZceHRPiMmgCmusvzbkQpcUbq6tvHbo8Ep4c=; b=miBl/r4qNbWQJCqpOJ8jX47ZXyO1skSpDYPH30pYS+qbo/XBi5u+JNxdYjh5tnB9WP JL930nRyOjgoOwcLaBuF3AeBPiXDNPut3ObCWtkjwKp8jGpdzw3L/YGSX2gmPTpvcvcn FDft2Bz1X01v+0/DYE+rvGnnCBaiv7E7canHA= 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=iPXqAroEMLQaaHUydJDS3bcfFSbY2CmVt03pI1AL13v3kflkIswUc0WVi3s8BXTq88 zOKwsmRnpLB1hHdDPQ5yqzu0MwJ3ijka/e2eKiFEfw3O7u7Ra05UQs2ZIqLZzkkMutXs A5zLF3RJuWEjvpiHIMdDVM+wPKplTNzEZMqYI= Received: by 10.204.156.217 with SMTP id y25mr3279138bkw.2.1268507330865; Sat, 13 Mar 2010 11:08:50 -0800 (PST) Received: from gumby.homeunix.com (bb-87-81-140-128.ukonline.co.uk [87.81.140.128]) by mx.google.com with ESMTPS id l1sm11873687bkl.14.2010.03.13.11.08.49 (version=SSLv3 cipher=RC4-MD5); Sat, 13 Mar 2010 11:08:49 -0800 (PST) Date: Sat, 13 Mar 2010 19:08:38 +0000 From: RW To: freebsd-questions@freebsd.org Message-ID: <20100313190838.2197cdc8@gumby.homeunix.com> In-Reply-To: <4B9BD37E.1060801@infracaninophile.co.uk> References: <3f1c29e71003120257h23ecc310w730bbc6396b27a37@mail.gmail.com> <795fc2b81003120622o2162463dv6697e26a86188cbe@mail.gmail.com> <20100312145405.742da070@gumby.homeunix.com> <3f1c29e71003120706q692fbc1cgebd2463dcf95b35d@mail.gmail.com> <20100312152732.377a92a2@gumby.homeunix.com> <86r5npun1e.fsf@blue.stonehenge.com> <3f1c29e71003130647x8e78411w82fcdde6f1f78479@mail.gmail.com> <4B9BD37E.1060801@infracaninophile.co.uk> X-Mailer: Claws Mail 3.7.5 (GTK+ 2.18.7; i386-portbld-freebsd8.0) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: ntpdate problem 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: Sat, 13 Mar 2010 19:08:53 -0000 On Sat, 13 Mar 2010 18:03:42 +0000 Matthew Seaman wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 >=20 > On 13/03/2010 14:47:31, =D0=90=D0=BD=D1=82=D0=BE=D0=BD =D0=9A=D0=BB=D0=B5= =D1=81=D1=81 wrote: > > I saw that more than year ago on my teacher's server, when I was > > deal with my first FreeBSD, so it's just a kind of habit. >=20 > It's a bad habit you should try and cure yourself of. Stepping the > clock with ntpdate(8) can cause nasty effects like time apparently > going backwards -- and that will seriously upset a lot of software. >=20 > Also, it doesn't account for the natural clock drift of your system, > so it's going to give you pretty terrible accuracy -- probably good > to no more than a few seconds. ntpdate(8) is really only intended to > get the clock into the right ballpark at system boot so that ntpd(8) > has a fighting chance of getting into synch. The NTP project has > deprecated ntpdate(8) for some time now, and instead prefers adding > an option to ntpd(8) to say "set the clock on initial startup no > matter how far out it is." >=20 > > But on the other hand, if it exists, it could work properly, and I > > am interested in just to understand, how it should be set up. >=20 > I'm assuming you're on some sort of always-on network, like ADSL? > Most people are nowadays. In which case, there's really no reason > not to run ntpd(8) the way it is intended to be used. >=20 > Just add the following to /etc/rc.conf: >=20 > ntpd_enable=3D"YES" > ntpd_sync_on_start=3D"YES" >=20 ntpd_sync_on_start=3D"YES" is not a complete substitute for running ntpdate at startup. It allows ntpd to make a large correction, but it doesn't block the boot sequence so you could still get a large step-change later-on when your daemons are starting-up.=20 ntpd has an option to emulate ntpdate, but it holds-up the boot-sequence much longer - presumably this is why ntpdate has been deprecated for a long time but hasn't yet gone away.=20 you can run ntpdate at boot with ntpdate_enable=3DYES the rc script gets the servers from ntp.conf