[TriLUG] Ubuntu and KVM
bdmc at bdmcc-us.com
Wed Aug 19 15:33:07 EDT 2009
On Wed, Aug 19, 2009 at 02:12:59PM -0400, Jason Herr wrote:
> I ran into this earlier... Here's what I used for Ubuntu:
Yup. Been there several times.
> Basically, you set up a bridge interface and run your server's network
> through it.
That has been done in several ways. I'll talk about them later.
> You can then configure the vm's xml file to use it and/or
> put the change into the template file for libvirt. There are
> side-effects. Root access is needed to bring up the tap access for the
I'm not certain that that is correct. As I said, I am inheriting this.
I did make a copy of the libvirt.xml ( was that the name ) file and
removed references to the "default" network, but I suspect that that
isn't being used yet.
> There were assumptions made in that document that I'm still not sure I
> get. NetworkManager fights against that process pretty hard, so you'll
> need to disable it (my update to the wiki).
Yes, it's already been removed from the machine.
> Also, I'd suggest doing
> this configuration change locally or via a IP-based KVM switch since
> you're so far away. My server got knocked off the net doing this the
> first time.
Yup. Been there, did that a couple of times. Fortunately, except for
this last time, it recovered and I was able to get back in.
OK, back to /etc/network/interfaces. In the "host" machine, I found it
with br0 and br1, as well as several br0:x interfaces defined.
According to the wiki page, only br0 should be necessary, or is that
just an "example" simplification?
Every time that I have got close to the example configuration, the host
machine's communications have got very shakey.
This last time, I put in exactly that example configuration ( with my
own IP, netmast, etc. ) and it really went away. I am just waiting for
someone on the left coast to get into the colo and attach and read the
console for me.
If I had it working, should the system automatically assign a br0:99 for
the new guest ( child ) when it starts?
That's the behaviour that I remember from when I was first building my
Xen machines. You don't do something frequently enough, and you lose
And, as I suspect you are going to say, if I made sure that the
libvirt.xml file ONLY said Bridge, this would be true.
Thank you for the guidance,
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