Windows+VirtualBox+Ubuntu+Xen+Ubuntu

What we have:

    Native machine installed with Windows 7.

Now I want to play with some virtual machines:

    1. Install VirtualBox into Windows 7, as a VM
    2. Install Ubuntu(1) into VirtualBox, as a guest OS
    3. Install Xen into Ubuntu, as a VM
    4. Install Ubuntu(2) into Xen, as a guest OS

Versions:
    VirtualBox 4.3.10 r93012
    Ubuntu 14.04 Server 
    Xen 4.4


It is quite easy to install Ubuntu into VirtualBox (step1 and step2). One thing to remember: "Do not assign all allocated space to Ubuntu(1)". Supposedly we decide to give 100GB disk space to VMs inside the VirtualBox, then the Ubuntu(1), as a dom0 OS, should use as less space as possible, say, 2GB. The remaining 98GB disk space should be reserved for one or more guest Ubuntu(2) guest OS. Otherwise your Xen will hang up when trying to "brought up CPU".


#1. get the Xen package
$sudo apt-get install xen-hypervisor-4.4-amd64

#2. Set Xen as the default loading OS
$sudo sed -i 's/GRUB_DEFAULT=.*\+/GRUB_DEFAULT="Xen 4.4-amd64"/' /etc/default/grub
sudo update-grub

#3. use xl as toolstack
$sudo sed -i 's/TOOLSTACK=.*\+/TOOLSTACK="xl"/' /etc/default/xen
$sudo reboot

$sudo xl list

#4. Create primary partition on remaining disk space
sudo fdisk /dev/sda

... /dev/sda3

#5. restart 

sudo reboot

#6. create physical storage

sudo pvcreate /dev/sda3

#7. create volume group "xen-vg" on /dev/sda3

sudo vgcreate xen-vg /dev/sda3

#8. take a look at PVs. 

sudo pvs

  PV         VG     Fmt  Attr PSize  PFree

  /dev/sda3  xen-vg lvm2 a--  51.62g 51.62g

#9. create logical volume "ubuntu" guest OS with 10G disk space

sudo lvcreate -L 10G -n ubuntu /dev/xen-vg

#10. Tell it where to get the image - Ubuntu 14.40 (a.k.a utopic)

sudo mkdir -p /var/lib/xen/images/ubuntu-netboot

$cd /var/lib/xen/images/ubuntu-netboot

$sudo wget http://ubuntu.cs.utah.edu/ubuntu/dists/utopic/main/installer-amd64/current/images/netboot/xen/initrd.gz

$sudo wget http://ubuntu.cs.utah.edu/ubuntu/dists/utopic/main/installer-amd64/current/images/netboot/xen/vmlinuz

#11. Configuration

$sudo vim /etc/xen/ubuntu.cfg

name = "ubuntu"

memory = 512

disk = ['phy:/dev/xen-vg/ubuntu,xvda,w']

vif = [' ']

kernel = "/var/lib/xen/images/ubuntu-netboot/vmlinuz"

ramdisk = "/var/lib/xen/images/ubuntu-netboot/initrd.gz"

extra = "debian-installer/exit/always_halt=true -- console=hvc0"

#12. Start installing the Ubuntu(2) 

sudo xl create /etc/xen/ubuntu.cfg -c  

Reference 

https://help.ubuntu.com/community/Xen