How To Set Up Xen 3.0 From Binaries In Ubuntu 6.06 LTS (Dapper Drake)
Author: Ásgeir Bjarni Ingvarsson <istari AT hlekkir DOT com>
Last Edited: June 13. 2006
This particular way of installing and configuring Xen is just the path of least resistance for me. There are many other possible ways of configuring the system.
1 Install a clean base server system.
Setup Ubuntu like you normally would. I have created 3 partitions on hda, but you can do it any way you like. Just keep your differences in mind when you edit the config files.
- hda1 is swap
- hda2 is 2 GB and mounted as /
- hda3 is the rest of the disk and mounted as /xen-images
2 Update the system and install Xen
2.1 Install Xen and configure it
Open a root shell so you don't have to type sudo for every command.
Update the system and install nessecary packages.
apt-get install iproute python python-twisted bridge-utils debootstrap
Download and extract the Xen 3.0 tarball from XenSource.
tar xvf xen-3.0.1-install-x86_32.tgz
Check for error messages - it should say OK to all.
Next we create modules.dep and map files for the new kernel. (see /lib/modules for the correct kernel version)
/sbin/depmod -a 2.6.16-xen
Edit /etc/mkinitramfs/modules and append the following line:
If you run out of loop devices later just increase max_loop and rebuild the initrd.
Create an initrd image. Use the same version number as before.
mkinitramfs -o initrd.img-2.6.16-xen 2.6.16-xen
Edit /boot/grub/menu.lst placing the following lines before the Automagic section
title Xen 3.0 / XenLinux 2.6
module /boot/vmlinuz-2.6-xen root=/dev/hda2 ro
Make Xen start up and autostart selected guests when the system starts up. xend must start before, and must be stopped after xendomains.
update-rc.d xend start 30 2 3 4 5 . stop 31 0 1 6 .
update-rc.d xendomains start 31 2 3 4 5 . stop 30 0 1 6 .
Disable Thread-Local Storage (remember to check this after every update)
mv /lib/tls /lib/tls.disabled
2.2 The following workarounds may not be required later, but I had to do them.
mv /etc/udev/rules.d/xen-backend.rules /etc/udev/rules.d/92-xen-backend.rules
To make sure that /var/run/xenstored and /var/run/xend exist. Edit /etc/init.d/xend and insert the following lines after the check for /proc/xen/capabilities
if [ ! -d /var/run/xend ] ; then
mkdir -p /var/run/xend
if [ ! -d /var/run/xenstored ] ; then
mkdir -p /var/run/xenstored
Edit /etc/init.d/xendomains and change the LOCKFILE line to read
2.3 All done for this part so reboot.
When the system is back up try the following command to verify that everything is ok.
You should see something similar to this:
Name ID Mem(MiB) VCPUs State Time(s)
Domain-0 0 463 1 r----- 42.3
3 Configuring the guest domains
3.1 Create disk images and bootstrap them
Create a mountpoint for the images.
mkdir -p /xen-images/mnt
Create a 1 GB image file and 500 MB swap file, for larger images increase count.
dd if=/dev/zero of=/xen-images/guest_base.img bs=1024k count=1000
dd if=/dev/zero of=/xen-images/guest_base-swap.img bs=1024k count=500
Change permissions for the image files. No one should have access to your Domain-0 computer since that would compromise security for all of the guest domains, but this is a good idea anyway and doesn't affect Xen.
chmod 640 /xen-images/guest_base*
Format guest_base.img as ext3 and then format guest_base-swap.img as swap. When it says "/xen-images/guest_base.img is not a block special device." answer yes to proceed anyway.
Mount the guest image and bootstrap it. You should replace http://archive.ubuntu.com/ubuntu/ with a mirror that is closer to you.
mount -o loop /xen-images/guest_base.img /xen-images/mnt
debootstrap --arch i386 dapper /xen-images/mnt http://archive.ubuntu.com/ubuntu/
Copy your /etc/apt/sources.list to the new image
cp /etc/apt/sources.list /xen-images/mnt/etc/apt/
Copy the kernel modules.
cp -dpR /lib/modules/2.6.16-xen /xen-images/mnt/lib/modules/
Disable Thread-Local Storage.
mv /xen-images/mnt/lib/tls /xen-images/mnt/lib/tls.disabled
Configure networking for the guest by editing /xen-images/mnt/etc/network/interfaces
# The loopback network interface
iface lo inet loopback
# The primary network interface
# Uncomment this and configure after the system has booted for the first time
#iface eth0 inet static
# address 192.168.0.101
# netmask 255.255.255.0
# broadcast 192.168.0.255
# gateway 192.168.0.1
# dns-nameservers 192.168.0.1
Create /xen-images/mnt/etc/hosts and make it look like this.
127.0.0.1 localhost localhost.localdomain
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
echo guest > /xen-images/mnt/etc/hostname
Edit /xen-images/mnt/etc/fstab so it looks like this.
proc /proc proc defaults 0 0
/dev/hda1 / ext3 defaults,errors=remount-ro 0 1
/dev/hda2 none swap sw 0 0
Unmount the image.
If you get this warning "umount: /xen-images/mnt: device is busy" don't worry, it's not important.
3.2 Boot up the base image to finalize the configuration
Create a config file for the guest /etc/xen/baseimage
# -*- mode: python; -*-
kernel = "/boot/vmlinuz-2.6.16-xen"
ramdisk = "/boot/initrd.img-2.6.16-xen"
memory = 128
name = "baseimage"
vif = ['bridge=xenbr0']
disk = ['file:/xen-images/guest_base.img,hda1,w','file:/xen-images/guest_base-swap.img,hda2,w']
ip = "192.168.0.101"
netmask = "255.255.255.0"
gateway = "192.168.0.1"
hostname = "baseimage"
root = "/dev/hda1 ro"
extra = "4"
Start the guest.
xm create baseimage -c
Login as root and set the root password.
Enable shadow passwords.
Create a backup of /etc/network/interfaces
cp /etc/network/interfaces /etc/network/interfaces.bak
Edit /etc/network/interfaces and put in correct values so you can access the Internet
Install packages (add ubuntu-desktop and more if you want).
apt-get install ubuntu-base configure-debian openssh-server
Disable Thread-Local Storage if it has been updated.
mv /lib/tls /lib/tls.disabled
Configure the system any way you like, I recommend that you try every menu item. You should do utils->console-data before utils->console-common.
Add the new user you created to /etc/sudoers
Replace /etc/network/interfaces with the backup copy.
mv /etc/network/interfaces.bak /etc/network/interfaces
You are now done setting up the base image so shut it down.
4 Creating your first guest domain
Make a copy of the base guest images.
cp /xen-images/guest_base.img /xen-images/guestdom1.img
cp /xen-images/guest_base-swap.img /xen-images/guestdom1-swap.img
Make a copy of /etc/xen/baseimage for the new guest.
cp /etc/xen/baseimage /etc/xen/guestdom1
Edit /etc/xen/guestdom1 and change name, disk and hostname to the following values.
name = "guestdom1"
disk = ['file:/xen-images/guestdom1.img,hda1,w','file:/xen-images/guestdom1-swap.img,hda2,w']
hostname = "guestdom1"
You will want to change the following files for each new guest you create.
To make the guest start up automatically and make Domain 0 wait for it before shutting down.
ln -s /etc/xen/guestdom1 /etc/xen/auto/
Or if you want to start and stop the guest manually.
xm create guestdom1
For further information check the Xen documentation