[libvirt-users] Bringing up a guest with network disabled

James Gibbon james.gibbon at virgin.net
Tue Oct 1 13:29:31 UTC 2013


On Tue, 01 Oct 2013 06:10:46 -0600
Eric Blake <eblake at redhat.com> wrote:

> On 10/01/2013 06:04 AM, James Gibbon wrote:
> > 
> > 
> > Hello all,
> > 
> > I have a KVM guest VM which is a clone of a production machine
> > running on a different physical server, incarnated from an 
> > image backup.
> 
> Careful.  You need to scrub more than just the IP address for a
> clone and it's parent to safely run at the same time.  For
> example, if you don't scrub the entropy pool, then one of the
> two machines will now have predictable "random" numbers just by
> watching what the other host did, which is horrible from a
> security perspective.  I highly recommend the use of
> 'virt-sysprep' on the image backup prior to creating your
> clone, which will not only scrub the IP address, but everything
> else that ought to be unique between a clone that is intended
> to run alongside the parent.  Once you start from a clean
> image, then the question about starting the guest with network
> disabled may be moot.
> 

Thanks, looks really useful but unfortunately I don't have it
on this particular machine, which is going to be decommissioned
in a few weeks anyway. The cloned VM will only be used for
testing purposes, and only for a short time. Would be grateful if
someone could suggest a way to disable the networking in the
cloned VM within the XML, if that's possible.

Thanks again,
James




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