From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Wright Subject: Re: Memory allocation going seriously wonky on 4.1.1 Date: Mon, 03 Oct 2011 14:45:36 +0100 Message-ID: <4E89BC80.4030105@overnetdata.com> References: <4E85DB1A.5060606@overnetdata.com> <20111001120706.GZ12984@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20111001120706.GZ12984@reaktio.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: =?ISO-8859-1?Q?Pasi_K=E4rkk=E4inen?= Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 01/10/2011 13:07, Pasi Kärkkäinen wrote: > On Fri, Sep 30, 2011 at 04:07:06PM +0100, Anthony Wright wrote: >> I have a machine with 16GB of RAM running 32 bit xen 4.1.1 with Dom0 >> running a 3.0.4 linux kernel and 23 paravirtualized DomUs. >> > Hey, > > Why 32bit Xen? I think all (most?) hypervisor testing happens with 64bit Xen. > Note that you can still have 32bit dom0 kernel with 64b hypervisor. I'm going to investigate 64 bit xen on a 32 bit Dom0 soon, but as to the 32 xen, I work quite a lot with older hardware and Xen since it does paravirtualisation, and it's a really good way to re-use old hardware. >> As the free ram gets to 2391 MB free the system behaves as if it's got >> no more ram, and starts grabbing ram from Dom0, before getting even more >> confused and failing to start DomUs and eventually crashing the whole >> machine. I have attached a tarball with the output of xl dmesg, xl info >> & xl list at various points. >> > - Do you use dom0_mem= parameter for Xen? > - Did you disable dom0 ballooning? > > http://wiki.xen.org/xenwiki/XenBestPractices I was already using the dom0_mem= parameter on the xen hypervisor, but I disabled dom0 ballooning (enable-dom0-ballooning no), and just for good measure I also set (dom0-min-mem 2000). This had no effect, when I increase the 10-4 memory requirements, on restart the Dom0 memory is reduced to 1713MB and xl info reports 2391MB free. >> Stage 1 >> Everything is fine, Dom0 has 2000MB according to xl list, and 'xl info' >> says there is 2405MB free. > - How much memory did dom0 initially have? > - Did you use mem= parameter for dom0 kernel (vmlinuz) ? > > See: http://wiki.xen.org/xenwiki/Linux_30_bugs dom0 starts with 2000MB. I didn't use mem= on the linux kernel - I thought it wasn't neccessary.