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Re: [Xen-users] Memory problems persist... Cannot allocate memory

To: James Pifer <jep@xxxxxxxxxxxxxxxx>
Subject: Re: [Xen-users] Memory problems persist... Cannot allocate memory
From: Pasi Kärkkäinen <pasik@xxxxxx>
Date: Thu, 31 Dec 2009 18:46:56 +0200
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On Thu, Dec 31, 2009 at 10:45:13AM -0500, James Pifer wrote:
> > How do you check this 'free memory'? from dom0, or from Xen hypervisor
> > "xm info" ?
> Yes, from xm info.
> > Have you dedicated memory to dom0? ie. have you specified dom0_mem=512M
> > (or whatever you need) in grub.conf for xen.gz ? 
> Yes:
> kernel /boot/xen.gz  dom0_mem=2048M
> > 
> > In addition to dom0_mem for Xen hypervisor, you should also have
> > dom0-min-mem= specified in /etc/xen/xend-config.sxp to prevent dom0 from
> > being ballooned down.
> # dom0-min-mem is the lowest permissible memory level (in MB) for dom0.
> # This is a minimum both for auto-ballooning (as enabled by
> # enable-dom0-ballooning below) and for xm mem-set when applied to dom0.
> (dom0-min-mem 512)
> # Whether to enable auto-ballooning of dom0 to allow domUs to be
> created.
> # If enable-dom0-ballooning = no, dom0 will never balloon out.
> (enable-dom0-ballooning no)
> Should this match the mem set at the kernel level or is this ok?

Looks like you don't have dom0 ballooning enabled, so then dom0 should
always have the dedicated 2048 MB of memory.

What was the error you got? check dom0 "dmesg", "xm dmesg" and "xm log"
when creating 15/16+ guests..

-- Pasi

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