From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pasi =?iso-8859-1?Q?K=E4rkk=E4inen?= Subject: Re: Re: [Xen-users] Max. PV and HVM Guests Date: Mon, 9 Nov 2009 14:05:57 +0200 Message-ID: <20091109120557.GG16033@reaktio.net> References: <1257685302.5339.11.camel@k2000.jpp.fr> <20091109115458.GF16033@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Mr. Teo En Ming (Zhang Enming)" Cc: jp.pozzi@izzop.net, xen-devel@lists.xensource.com, xen-users@lists.xensource.com, Robert Dunkley List-Id: xen-devel@lists.xenproject.org On Mon, Nov 09, 2009 at 08:01:00PM +0800, Mr. Teo En Ming (Zhang Enming) = wrote: > No, I didn't limit dom0 memory in grub.conf. >=20 You should.=20 If dom0 has all the memory at boot time, you need to balloon down dom0=20 memory every time you create a new guest - this can (and will) cause=20 problems with the dom0 linux kernel. Linux calculates some internal parameters/buffers/values based on the _boot time_ amount of memory. And when the amount of memory goes down to only a small fraction of that while creating new guests bad things can happen.. It still shouldn't crash though.. I bet your problem will get fixed when you limit the dom0 memory to say dom0_mem=3D512M and reboot. -- Pasi > Here's my xm info output after I have shutdown all the virtual machi= nes. >=20 > [root@fedora11-x86-64-host ~]# xm list > Name ID Mem VCPUs Stat= e > Time(s) > Domain-0 0 2812 2 r----= - > 3242.5 > [root@fedora11-x86-64-host ~]# xm info > host : fedora11-x86-64-host > release : 2.6.30-rc3-enming.teo-tip > version : #1 SMP Wed Aug 19 23:14:15 SGT 2009 > machine : x86_64 > nr_cpus : 2 > nr_nodes : 1 > cores_per_socket : 2 > threads_per_core : 1 > cpu_mhz : 2800 > hw_caps : > bfebfbff:20100800:00000000:00000140:0400e3bd:00000000:00000001:00000= 000 > virt_caps : hvm hvm_directio > total_memory : 6039 > free_memory : 3124 > node_to_cpu : node0:0-1 > node_to_memory : node0:3124 > xen_major : 3 > xen_minor : 5 > xen_extra : -unstable > xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_= 32 > hvm-3.0-x86_32p hvm-3.0-x86_64 > xen_scheduler : credit > xen_pagesize : 4096 > platform_params : virt_start=3D0xffff800000000000 > xen_changeset : Tue Sep 01 11:34:31 2009 +0100 20143:a7de5b= d776ca > xen_commandline : iommu=3D1 > cc_compiler : gcc version 4.4.1 20090725 (Red Hat 4.4.1-2= ) > (GCC) > cc_compile_by : root > cc_compile_domain : (none) > cc_compile_date : Thu Sep 10 07:01:13 SGT 2009 > xend_config_format : 4 >=20 > -- > Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanic= al > Engineering) > Alma Maters: > (1) Singapore Polytechnic > (2) National University of Singapore > My Primary Blog: [1]http://teo-en-ming-aka-zhang-enming.blogspot.com > My Secondary Blog: [2]http://enmingteo.wordpress.com > My Youtube videos: [3]http://www.youtube.com/user/enmingteo > Email: [4]space.time.universe@gmail.com > Mobile Phone (Starhub Prepaid): +65-8369-2618 > Street: Bedok Reservoir Road > Country: Singapore >=20 > On Mon, Nov 9, 2009 at 7:54 PM, Pasi K=E4rkk=E4inen <[5]pasik@iki.fi= > wrote: >=20 > On Mon, Nov 09, 2009 at 06:52:37PM +0800, Mr. Teo En Ming (Zhang E= nming) > wrote: > > Hi, > > > > Please watch this 4-minute video at > > [1][6]http://www.youtube.com/watch?v=3DLbLaPpwNAx4 > > > > I have only started 3 HVM Linux guests with 1 GB ram each. I = can't > start > > the 4th HVM guest. If I attempt to start the 4th instance, it= will > crash > > dom0. > > > > Are there anything in the xm dmesg output that could explain = the > low limit > > to the number of VMs that I could start before dom0 becomes > unresponsive? > > >=20 > Have you limited dom0 memory (by specifying dom0_mem=3DXMB option = in > grub.conf for xen.gz) ? >=20 > What does "xm info" say about free memory before starting any gues= ts? > -- Pasi >=20 > References >=20 > Visible links > 1. http://teo-en-ming-aka-zhang-enming.blogspot.com/ > 2. http://enmingteo.wordpress.com/ > 3. http://www.youtube.com/user/enmingteo > 4. mailto:space.time.universe@gmail.com > 5. mailto:pasik@iki.fi > 6. http://www.youtube.com/watch?v=3DLbLaPpwNAx4