From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 812B61381F3 for ; Thu, 25 Apr 2013 23:51:34 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id E4424E0B00; Thu, 25 Apr 2013 23:51:18 +0000 (UTC) Received: from mail-we0-f182.google.com (mail-we0-f182.google.com [74.125.82.182]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 8A5E3E09C5 for ; Thu, 25 Apr 2013 23:51:17 +0000 (UTC) Received: by mail-we0-f182.google.com with SMTP id s43so3178054wey.13 for ; Thu, 25 Apr 2013 16:51:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:message-id:date:from:user-agent:mime-version:to:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=uB41EYsEcH7liuzEfxN6yb/e1VXRgVhTywwlTqRiLJY=; b=gZKmV6bRIroCn21jLUeIeJCxj2fr1cKytOM+RMNpaaG1h9z4/NLEf7B23iYRa7gp06 7Yl1yyd3nnI0aOIpCo1OzBtg8bVSEgOUnmwhrwjb/FdYXPYSzFdR0eFjNDui48g/T/hm g0sgAdjeqDChbVRMsOC9KyeuaASSaM/up55u1dtPBP2OgFLEtIVRa7GAlFlRdQbEDPQF ZAABfNJoTCugTN+Aaq52czOJ6eImK5Kq7SSEJayIdU0OzGdgeb8sGMKxVgBOWWZbmNZa khDCSaYZFeDowhpebfw87miosjOVyLqVKdlHWcdONfKqF8PxYWewWbVOFKM5czDrsgRz 0rjw== X-Received: by 10.180.20.108 with SMTP id m12mr732264wie.8.1366933876230; Thu, 25 Apr 2013 16:51:16 -0700 (PDT) Received: from [172.20.0.40] (196-215-203-210.dynamic.isadsl.co.za. [196.215.203.210]) by mx.google.com with ESMTPSA id nf9sm236180wic.3.2013.04.25.16.51.14 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 25 Apr 2013 16:51:15 -0700 (PDT) Message-ID: <5179C140.3070902@gmail.com> Date: Fri, 26 Apr 2013 01:50:24 +0200 From: Alan McKinnon User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130413 Thunderbird/17.0.5 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Server system date synchronizaion References: <51794585.5080502@libertytrek.org> <5179BF4C.9080007@iinet.net.au> In-Reply-To: <5179BF4C.9080007@iinet.net.au> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Archives-Salt: 443e2dd6-607a-4f22-80c2-a4044c35be86 X-Archives-Hash: ca44efa8ed6eb87a7b5b111d46126c22 On 26/04/2013 01:42, William Kenworthy wrote: > Does anyone know a good guide to using time sync in VM's, for both > windows and linux (gentoo) guests using libvirt? Especially for guests > that are resumed, or the whole virtualisation system is hibernated? (ntp > refuses to resync after guest pause/save/restore/resume (known problem), > even with "tinker panic 0" That's not a bug, it's by design. If ntpd detects the clock is out by more than X seconds [1], it will not try to correct the difference, concluding that something is wrong and a human must decide. It can't easily tell the difference between a resumed guest (or even that it was resumed at all) and a severe problem. We fixed this by taking the easy route of least resistance; 1. run ntpdate on startup/restart once before ntpd starts 2. start ntpd as normal 3. a colleague wrote a $MAGIC_HOOK to detect resumed guests that runs ntpdate once True, it's a brutal solution and uses a baseball bat where some finesse might be less ugly, but it suits our needs just fine. [1] I forget what X is and am too lazy to look it up. Is it 30 seconds or thereabouts? -- Alan McKinnon alan.mckinnon@gmail.com