[Fedora-xen] Xen only showing 16GB of ram out of 28GB

[thewird]

> > I installed FC6 and FC7 and the limit exists on both even though
> FC7
> > was supposed to be using a 64bit hypervisor which supports 32bit
> guests
> > (which isn't the case).
> 
> WorksForMe[tm].  Test box with a bunch of systems installed, among
> them
> fedora7 32bit and fedora7 64bit.  Booting the 32bit fedora dom0 with
> the
> 64bit hypervisor (aka /boot/xen.gz-<version>) from the 64bit
> installation works just fine.
> 
> If you got it right "xm dmesg" looks like this:
> [ ... ]
> (XEN)  Xen  kernel: 64-bit, lsb, compat32
> (XEN)  Dom0 kernel: 32-bit, PAE, lsb, paddr 0xc1000000 -> 0xc15e2000
> [ ... ]
> 
> The limitation is that the dom0 kernel backend drivers don't support
> 32-on-64, so you can't mix 32bit and 64bit domains.  As long as dom0
> and
> all guests are identical it works.
> 
> cheers,
>   Gerd
> 

I've tried this before. I installed FC7 32bit and replaced the xen.gz
with its 64bit version. Sure, it boots fine but when I try to boot
up/install a 32bit guest, the guest just hangs or pauses and will not
run even though the dom0 seems to be working just fine.

Marco Jorge