[[TOC(heading=KVM tutorial TOC, Tutorials/KVM)]]

= KVM Tutorial =
== Installing KVM ==

Check if your CPU supports hardware virtualization via command:
{{{
egrep '(vmx|svm)' --color=always /proc/cpuinfo
}}}
	
If nothing is displayed CPU doesn't support virtualization.

Instal packages ubuntu-virt-server, python-vm-builder and kvm-pxe via command (but just in case, first update the package repository on the node):
{{{
apt-get update
apt-get install ubuntu-virt-server python-vm-builder kvm-pxe
}}}
		
Add the current user to the group:
{{{
adduser `id -un` libvirtd
adduser `id -un` kvm
}}}
	
Logout and login again:
{{{
logout
ssh root@node1-1
}}}
	
Check users group by comamand:
{{{
groups
}}}

Output should be similar to:
{{{
root kvm libvirtd
}}}

To list all running KVMs use:
{{{
virsh -c qemu:///system list
}}}

== Setup network bridge on the host ==

Install the package bridge-utils:
{{{
apt-get install bridge-utils
}}}

Create the bridge interface named br0:
{{{
brctl addbr br0
}}}

Edit the network interfaces configuration with editor (for example nano):
{{{
nano /etc/network/interfaces
}}}

and add persistent configuration for br0 interface:
{{{
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth1
iface eth1 inet dhcp

# The secondary network interface
auto eth0
iface eth0 inet manual

#Bridge 0 interface
auto br0
iface br0 inet static
  address 10.28.1.1
  netmask 255.255.0.0
  broadcast 10.28.255.255
  network 10.28.0.0
  bridge_ports eth0
  bridge_fd 9
  bridge_hello 2
  bridge_maxage 12
  bridge_stp off
}}}

Restart networking with command:
{{{
/etc/init.d/networking restart
}}}

For bridge verification open the new ssh window and run:
{{{
tcpdump -i br0
}}}

and then, in the other window, try to ping some adress in same subnet, for example:
{{{
ping 10.28.0.1
}}}

In the second windows you should see logging ofrequest/reply messages.

It is recommended to reboot the machine once the bridge is configured.

== Create and run KVM image using vmbuilder ==

Folder /var/lib/libvirt/images/ will be created for storing images. Each image will have
separate folder for example /var/lib/libvirt/images/virtual-machine1

Create necessary folders:
{{{
mkdir -p /var/lib/libvirt/images/vm1/mytemplates/libvirt
}}}	
'-p' option of mkdir command means that all parent folders will be created if they do not exist.

vmbuilder tool uses templates for creating of images so copy the template:
{{{
cp /etc/vmbuilder/libvirt/* /var/lib/libvirt/images/vm1/mytemplates/libvirt/
}}}
	
Open partition configuration file with command:
{{{
nano /var/lib/libvirt/images/vm1/vmbuilder.partition
}}}

and add the following lines:
{{{
root 8000
swap 4000
---
/var 20000
}}}
	
Copied text defines three partitions - root, swap and var and their sizes.
"---" means that var partition will be separate image file.

Go to folder vm1:
{{{
cd /var/lib/libvirt/images/vm1/
}}}

Execute vmbuilder command:
{{{
vmbuilder kvm ubuntu --suite=oneiric --flavour=virtual --arch=amd64 --mirror=http://de.archive.ubuntu.com/ubuntu -o --libvirt=qemu:///system --ip=10.28.4.4 --gw=10.28.0.1 --mask=255.255.0.0 --bcast=10.28.255.255 --net=10.28.0.0 --dns=10.0.0.9 --part=vmbuilder.partition --templates=mytemplates --user=guest --name=Guest --pass=guest --addpkg=vim-nox --addpkg=unattended-upgrades --addpkg=acpid --mem=256 --hostname=vm1 --bridge=br0 --addpkg openssh-server --addpkg nano
}}}	

== Create and run KVM image using KVM directly ==

Download ubuntu server ISO file:
{{{
wget -O ubuntu-server.iso http://www.ubuntu.com/start-download?distro=server&bits=64&release=latest 
}}}

Create Disk:
{{{
qemu-img create -f qcow2 vm-oneric-amd64-serial 10G
}}}

Setup network bridge (see part III).

Install tool for Tun:
{{{
apt-get install uml-utilities
}}}

Create the tap interface:
{{{
tunctl
}}}

Output of the name is (tap0).

Add tap interface to the bridge as a port:
{{{
brctl addif br0 tap0
}}}

Bring up tap0 interface:
{{{
ifconfig tap0 up
}}}

Boot and Install Ubuntu using VNC:
{{{
kvm -daemonize -m 1024 -hda vm-oneric-amd64-serial -cdrom ubuntu-server.iso -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net tap,ifname=tap0,script=no -vnc :0
}}}	

To run already created image you can enter:
{{{
kvm -daemonize -m 1024 -hda vm-oneric-amd64-serial  -smp 2 -cpu qemu64 -net nic,model=virtio -net tap,ifname=tap0,script=no -vnc :0
}}}

Use VNC client to connect to virtual machine.
	
Kill Virtual machine (KVM process):
{{{
pkill -9 kvm
}}}

Remove tap0 in as a bridge interface:
{{{
brctl delif br0 tap0
}}}

Delete tap interface:
{{{
tunctl -d tap0
}}}

{{{
kvm -daemonize -m 1024 -hda vm-oneric-amd64-serial -smp 2 -cpu qemu64 -net nic,model=virtio -net tap,ifname=tap0,script=no -vnc :0
}}}

{{{
kvm -daemonize -m 1024 -hda vm-oneric-amd64-serial -cdrom ubuntu-11.10-server-amd64.iso -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net tap,ifname=tap0,script=no -vnc :0
}}}