[CentOS-virt] Xen network problem

Ken Bass kbass at kenbass.com
Fri Oct 30 21:53:48 UTC 2009

Ben M. wrote:
> Not trying to take this off-topic, I think it is relevant.
> Christopher: When I booted up with dom0-cpus 1, Windows 2008 could not 
> "find" its second cpu. However, once up, I can "xm or virt-manager" it 
> down to 1 cpu on cup 0 and everything is fine.
> Is this a unique issue or do you have a tweak or hack to force smp with 
> dom0 on one cpu?
While I was googling  I saw as mention that there was setting the 
dom0-cpus versus modifying the dom0 kernel argument with dom0_max_vcpus=1

It sounded like using the dom0-cpus method starts the boot process with 
all your CPUs and then it dynamically shinks down to the dom0-cpus level 
you specify when the xend task starts. The kernel argument method will 
limit the # of CPU's from the beginning. Not sure if this makes sense in 
your case since you are talking about Windows 2008.

I also went into each of my guest configs and added a 'cpus="x-y"' line 
to tell the guest which CPUs it was pinned to. I made sure to exclude 
the one dom0 was running on.

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