Hello, I was running Xen 3.0.3-1 from Debian Etch before and needed the dom0_memparameter to get my systems to boot. I have a new system running Lenny and Xen 3.2-1. I didn''t specify the dom0_mem= parameter in my grub config. Did I just get lucky with it booting, or is this likely to cause me problems down the line? Thanks, Jonathan _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sun, May 3, 2009 at 2:54 AM, Jonathan Anderson <jonathan.b.andersonr@gmail.com> wrote:> Hello, > I was running Xen 3.0.3-1 from Debian Etch before and needed the dom0_mem> parameter to get my systems to boot. > I have a new system running Lenny and Xen 3.2-1. I didn''t specify the > dom0_mem= parameter in my grub config. > Did I just get lucky with it booting, or is this likely to cause me problems > down the line?It''s not mandatory to have that parameter, but it''s considered best practice. When ommitted, dom0 will use all available memory and ballon-down as needed when domUs are started. Depending on what you have running on dom0, ballooning down MIGHT cause a problem. So if you know (for example) that you have 4G memory, 512M will be allocated to dom0 while the reset will be used for domUs, you should set something like kernel /xen.gz-3.3.1 dom0_mem=512M on grub.conf, and have this entry on /etc/xen/xend-config.sxp (dom0-min-mem 512) These will effectively prevents dom0 from ballooning down memory. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thank you for the info Fajar. Are there any guidelines on how much ram you need to keep in your dom0 for the qemu-dm processes and the like? -- Regards, Jonathan _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sun, May 3, 2009 at 11:26 AM, Jonathan Anderson <jonathan.b.andersonr@gmail.com> wrote:> > Thank you for the info Fajar. > Are there any guidelines on how much ram you need to keep in your dom0 for > the qemu-dm processes and the like?That depends on what you run on dom0 and what your distro is. Usually I give it 500MB on RHEL5.3 dom0 without GUI. This would give enough room for things like "yum update". If you''re low on resource try 250MB first, do what you usually do (start domUs, apt-get update, or whatever) and look at memory usage (htop is nice). If swap usage is 0 then its probably enough. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Unless there is a chance that you will want to balloon up Dom0 memory, I believe the entry in /etc/xen/xend-config.sxp should actually be as follows to completely disable ballooning: (dom0-min-mem 0) Dustin -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Fajar A. Nugraha Sent: Saturday, May 02, 2009 22:17 To: Jonathan Anderson Cc: xen-users@lists.xensource.com Subject: Re: [Xen-users] dom0_mem still needed? On Sun, May 3, 2009 at 2:54 AM, Jonathan Anderson <jonathan.b.andersonr@gmail.com> wrote:> Hello, > I was running Xen 3.0.3-1 from Debian Etch before and needed the dom0_mem> parameter to get my systems to boot. > I have a new system running Lenny and Xen 3.2-1. I didn''t specify the > dom0_mem= parameter in my grub config. > Did I just get lucky with it booting, or is this likely to cause meproblems> down the line?It''s not mandatory to have that parameter, but it''s considered best practice. When ommitted, dom0 will use all available memory and ballon-down as needed when domUs are started. Depending on what you have running on dom0, ballooning down MIGHT cause a problem. So if you know (for example) that you have 4G memory, 512M will be allocated to dom0 while the reset will be used for domUs, you should set something like kernel /xen.gz-3.3.1 dom0_mem=512M on grub.conf, and have this entry on /etc/xen/xend-config.sxp (dom0-min-mem 512) These will effectively prevents dom0 from ballooning down memory. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users