From owner-freebsd-stable@FreeBSD.ORG Sat Jan 21 12:36:47 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2F8201065673 for ; Sat, 21 Jan 2012 12:36:47 +0000 (UTC) (envelope-from ronald-freebsd8@klop.yi.org) Received: from smarthost1.greenhost.nl (smarthost1.greenhost.nl [195.190.28.78]) by mx1.freebsd.org (Postfix) with ESMTP id AB9ED8FC08 for ; Sat, 21 Jan 2012 12:36:46 +0000 (UTC) Received: from smtp.greenhost.nl ([213.108.104.129]) by smarthost1.greenhost.nl with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.69) (envelope-from ) id 1RoZwC-0004XA-Mw; Sat, 21 Jan 2012 13:20:53 +0100 Received: from dhcp-077-251-058-236.chello.nl ([77.251.58.236] helo=pinky) by smtp.greenhost.nl with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1RoZwD-0007Y1-0q; Sat, 21 Jan 2012 13:20:53 +0100 Content-Type: text/plain; charset=us-ascii; format=flowed; delsp=yes To: "FreeBSD Stable Mailing List" , "Martin Sugioarto" References: <4F15D643.8000907@rewt.org.uk> <20120118075049.289954e8@zelda.sugioarto.com> <20120121101842.786fc402@zelda.sugioarto.com> Date: Sat, 21 Jan 2012 13:20:51 +0100 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Ronald Klop" Message-ID: In-Reply-To: <20120121101842.786fc402@zelda.sugioarto.com> User-Agent: Opera Mail/11.60 (Win32) X-Virus-Scanned: by clamav at smarthost1.samage.net X-Spam-Level: / X-Spam-Score: 0.0 X-Spam-Status: No, score=0.0 required=5.0 tests=BAYES_50 autolearn=disabled version=3.2.5 X-Scan-Signature: 448baf4759cd3283a5930955cc61e1db Cc: Joe Holden Subject: Re: Timekeeping in stable/9 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Jan 2012 12:36:47 -0000 On Sat, 21 Jan 2012 10:18:42 +0100, Martin Sugioarto wrote: > Am Wed, 18 Jan 2012 07:50:49 +0100 > schrieb Martin Sugioarto : > >> I can confirm this on VirtualBox. I've been running WinXP inside >> VirtualBox and measured network I/O during downloads. It showed me >> very high download rates (around 800kB/s) while it's physically >> possible to download 200kB/s through DSL here (Germany sucks with >> DSL, even in largest cities, btw!). >> >> I correlated this behavior with high disk I/O on the host. That means >> that the timer issues on the virtual host appear when I start a >> larger cp job on the host. I also immediately thought that this has >> something to do with timers. > > Hi everybody, > > I just want to add some information on this. I tested a few things with > VirtualBox yesterday. > > I switched off ntpd on the host and tested if there are differences, > but the clock is working correctly on the host. I tested it a few times, > it is stable, as I expect it to be. > > It seems to be rather a software problem with VirtualBox. I can see that > when the host is under heavy load (CPU!) the guest does not get enough > runtime to adjust the clock correctly. After a few minutes there has > been a difference of 50 seconds between the host and guest clock. And > furthermore, I don't quite understand how the real time clock works in > VirtualBox but it seems to slide in the different directions causing > weird results with progress bars on MS-Windows XP. > > I just want to explain why I thought that I/O influences this. I have > got my hard disk encrypted, so it puts some load on the CPU, too. > > If you want to test VirtualBox behavior, you can simple dd > from /dev/random and look at the weird results in VirtualBox. > > -- > I hope it helps further, > Martin Hi, As I understand it. Host: FreeBSD 9 Guest: WinXP Which one has troubles with its clock? The host or the guest or both? How many CPU's did you assign to the guest? Did you install virtualbox guest additions to the guest? Do you run NTP on the guest XP also? If yes, turn it off. VBox guest additions can sync the guest clock with the host. BTW: My experience with VBox is that it is nice for hobby stuff, but not for heavy load server stuff. VMWare does a better job there. Ronald.