On Wed, Jan 2, 2013 at 3:29 AM, <sg at cyon.ch> wrote: > Hi, > > I'm running CentOS 6.2 x86_64 as xen guest on a CentOS 5.7 dom0. > The host is running 2.6.18-274.7.1.el5xen, the guest > 2.6.32-220.2.1.el6.x86_64. > > Memory for domU is set to 1024 MB and "xm list" shows these 1024 MB. > But "free -m" on the guest system shows only 652 MB. > When I set up a CentOS 5.x guest with 1024 MB "free -m" shoes 1024 MB. > > Anyone else seeing this? Any ideas on how to fix it? Start out by doing all the updates to both the Hyperviisor and the guest. There have been ongoing improvements to kernels, and to libvirt, and ongoing security updates for numerous packages. You should realy be at CentOS 6.3 and CentOS5.8, respectively: CentOS 6.2 and CentOS 5.7 aren't even available on the main download mirrors, anymore.