[KVM and OVS] Installing KVM and Open vSwitch on Ubuntu

These articles provides a very good explanation about how to install KVM and Open vSwitch on Ubuntu.
http://blog.scottlowe.org/2012/08/17/installing-kvm-and-open-vswitch-on-ubuntu/
http://networkstatic.net/installing-open-vswitch-with-kvm/

I summarize the scripts from the above URLs as follows:

• ### Installing KVM and Open vSwitch on Ubuntu ###

sudo apt-get update && apt-get dist-upgrade

sudo apt-get install kvm qemu-kvm libvirt-bin virtinst virt-manager

sudo virsh net-destroy default

sudo virsh net-autostart --disable default

sudo aptitude purge ebtables

• ### Open vSwitch on Ubuntu ###

sudo apt-get install openvswitch-controller openvswitch-brcompat \

sudo openvswitch-switch openvswitch-datapath-source

# Edit this: /etc/default/openvswitch-switch and change this line:

  #BRCOMPAT=no ==> #BRCOMPAT=yes 

# to build and install the necessary module

sudo module-assistant auto-install openvswitch-datapath

• ### Add Open vSwitch bridge ###

sudo ovs-vsctl add-br br0
sudo ovs-vsctl add-port br0 eth0
sudo ovs-vsctl list port

• ### Change your eth0 IP to your new br0 interface ###

sudo ifconfig eth0 0
sudo ifconfig br0 192.168.1.x netmask 255.255.255.0
sudo route add default gw 192.168.1.1 br0

These two scripts bring up the KVM Tap interfaces into your
bridge from the CLI.

$ cat /etc/ovs-ifup
#!/bin/sh
switch='br0'
/sbin/ifconfig $1 0.0.0.0 up
ovs-vsctl add-port ${switch} $1

$ cat /etc/ovs-ifdown
#!/bin/sh
switch='br0'
/sbin/ifconfig $1 0.0.0.0 down
ovs-vsctl del-port ${switch} $1

#Then make executable
chmod +x /etc/ovs-ifup /etc/ovs-ifdown

• ### BOOT HD IMG ###

Here are some KVM examples. Starting with the CD is easiest. No build needed for testing.

sudo kvm -m 1024 -hda /media/Storage/imgs/centos.kvm -net nic,macaddr=00:11:22:CC:CC:C5 -net tap,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown &
OS Install

sudo kvm -m 512 -hda /media/Storage/imgs/centos.kvm -net nic,macaddr=00:11:22:CC:CC:C5 -net tap,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown -cdrom /media/Storage/vm-images/CentOS-6.2-x86_64-LiveCD.iso &
CD Boot

sudo kvm -m 512 -net nic,macaddr=00:11:22:CC:CC:10 -net tap,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown -cdrom /HD/Storage/vm-images/ubuntu-11.10-desktop-amd64.iso &
Make an Image from CD

sudo qemu-img create -f qcow2 /media/Storage/imgs/uCentOS-6.2.img 6G