From owner-freebsd-emulation@freebsd.org Tue Sep 22 19:26:47 2015 Return-Path: Delivered-To: freebsd-emulation@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 13831A07E87 for ; Tue, 22 Sep 2015 19:26:47 +0000 (UTC) (envelope-from la5lbtyi@aon.at) Received: from smtpout.aon.at (smtpout.aon.at [195.3.96.115]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 3EBA61DBC for ; Tue, 22 Sep 2015 19:26:45 +0000 (UTC) (envelope-from la5lbtyi@aon.at) Received: (qmail 12258 invoked from network); 22 Sep 2015 19:26:42 -0000 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on WARSBL608.highway.telekom.at X-Spam-Level: Received: from 88-117-68-209.adsl.highway.telekom.at (HELO gandalf.xyzzy) ([88.117.68.209]) (envelope-sender ) by smarthub85.res.a1.net (qmail-ldap-1.03) with AES256-SHA encrypted SMTP; 22 Sep 2015 19:26:42 -0000 X-A1Mail-Track-Id: 1442950001:12238:smarthub85:88.117.68.209:1 Received: from mizar.xyzzy (mizar.xyzzy [192.168.1.19]) by gandalf.xyzzy (8.15.2/8.15.2) with ESMTP id t8MJQfQN008199; Tue, 22 Sep 2015 21:26:41 +0200 (CEST) (envelope-from la5lbtyi@aon.at) Subject: Re: VirtualBox mangles memory To: =?UTF-8?Q?Bernhard_Fr=c3=b6hlich?= References: <55FE9662.7000406@aon.at> <1442866256.1127084.389759513.29E96282@webmail.messagingengine.com> <56017026.6040809@aon.at> Cc: freebsd-emulation@freebsd.org, Mark Felder From: Martin Birgmeier X-Enigmail-Draft-Status: N1110 Organization: MBi at home Message-ID: <5601AB71.9000003@aon.at> Date: Tue, 22 Sep 2015 21:26:41 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: freebsd-emulation@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Development of Emulators of other operating systems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Sep 2015 19:26:47 -0000 I don't think it is related to zfs. The 8GB machine did not even have zfs loaded or a zfs file system when I first reported the problem. (The problem with 'zfs send' only happened recently on the 16GB machine.) I'd like to know what has changed between FBSD 9 and 10 regarding memory management and maybe memory tuning parameters. I am quite sure that the cause is to be found there, and in VirtualBox not properly taking into account these changes. Maybe it is just some page table or similar temporarily running out of entries. The problem is easy to reproduce, so if I get some good hints on what to tune I can check whether they help. -- Martin On 09/22/15 20:50, Bernhard Fröhlich wrote: > > To me this sounds a lot like vbox and zfs arc are fighting for > resources. What does the memory line in top look like when this > problem happens? > > A simple workaround would be to limit zfs arc in loader.conf if that > is the problem. > > Am 22.09.2015 5:13 nachm. schrieb "Martin Birgmeier" >: > > > > This did not happen when the machine was running FreeBSD 9.2 with > virtualbox-ose-4.3.20 installed. So I would not qualify this as "known > behavior". > > > > One server has 16G main memory, a VM gets 3G. The other has 8G main > mem and again 3G allocated to the VM. > > > > This is definitely a bug in how VirtualBox handles memory on FreeBSD > 10. I am pretty sure that something changed in FBSD 10 which was not > properly taken care of in VB. > > > > -- Martin > > > > > > > > On 09/21/15 22:10, Mark Felder wrote: > > > > > > On Sun, Sep 20, 2015, at 06:20, Martin Birgmeier wrote: > > >> On machines where VirtualBox is running, I get memory allocation > errors. > > >> > > >> 'dd' aborts with 'dd: stdout: Cannot allocate memory' > > >> > > >> 'zfs send' aborts with 'internal error: Cannot allocate memory' > > >> > > >> I have created > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=195970 > > >> to track this. > > >> > > >> Could a knowledgeable person please have a look into this? > > >> > > >> FreeBSD 10.2, VirtualBox 4.3.30 > > >> > > >> -- Martin > > >> > > > I'm not an expert, but I think this is known behavior. Virtualbox > > > requires a huge contiguous chunk of memory for the VM and that's > > > probably what you're running into. > > > > > > Can you give more information about the specs of the server itself and > > > the amount of resources allocated to VMs? > > > > > > > _______________________________________________ > > freebsd-emulation@freebsd.org > mailing list > > https://lists.freebsd.org/mailman/listinfo/freebsd-emulation > > To unsubscribe, send any mail to > "freebsd-emulation-unsubscribe@freebsd.org > " >