Yet Another Linux Blog

This is on CentOS5, default Xen packages.

===Physical interfaces===
The physical machine has three GigE interfaces: eth0,eth1,eth2. eth0 is currently not connected to anything. eth1 is connected to a public network, e.g. xxx.xx.xx.0/23. eth2 is connected to a private network, e.g. 10.10.0.0/8.

===Virtual interfaces===
We want to have the same setup for the VMs, two interfaces, one private, one public. Thanks to the wonder of Free Software, this is very easy.

#make new script called /etc/xen/scripts/network-bridge-2
#modify /etc/xen/xend-config.sxp to use network-bridge-2 instead of network-bridge

The contents of network-bridge-2:

#!/bin/sh
dir=$(dirname "$0")
"$dir/network-bridge" "$@" vifnum=2 netdev=eth2
"$dir/network-bridge" "$@" vifnum=1 netdev=eth1

It simply calls network-bridge which creates the bridges and vifs, etc.

Look at ‘brctl show’ for information or ‘/etc/xen/scripts/network-bridge status’

===domU===
In the domU config file, simply specify which virtual interface belongs to which bridge:

vif = [ 'mac=00:16:3e:01:01:9f, bridge=xenbr1', 'mac=00:16:3e:01:01:9e, bridge=xenbr2', ]

They will show up in order as eth0, eth1…

===References===
(in order of usefulness):
#http://wiki.xensource.com/xenwiki/XenNetworking
#http://lists.xensource.com/archives/html/xen-users/2007-07/msg00800.html
#http://felipe-alfaro.org/blog/2006/07/21/xen-network-configuration-and-multiple-vlans/
#http://www.shorewall.net/XenMyWay-Routed.html

You learn something new every day!

I brought home the standard WinXP Pro with SP2 “volume license” media that I use for WinXP reinstalls, and put it in my home computer and booted from it and it said “Windows is inspecting your hardware configuration” and then there was a black screen and that’s it. The CD spins down shortly thereafter, and the machine just sits there with a blank screen. I tried it in another machine at home, same exact result! I tried it in a third machine, same exact result! How odd. The common part is that they’re all standard Linux installs, either Ubuntu Feisty or CentOS 5, with default partitioning schemes.

Searching Google for ‘blank screen “setup is inspecting your hardware configuration”‘ shows many threads where the question is asked but not answered. It seems that many people are in this same situation. However, one thread mentioned that blanking the HD first may help. So I booted the target machine back into Linux, wiped the partition table, rebooted with the Windows CD. It worked!

Conclusion: If you have a standard Linux partitioning scheme on your HD, the WinXP Pro boot CD will just hang after the “setup is inspecting your hardware configuration” message. Erase the partition table on the HD and it will work.