I want to create a bootable Live-USB to be able to run Ubuntu on any machine I need, independently of its hardware specs. As there are some Pentium III and IV still around, how should I proceed to enable Unity 2D on my live session by default instead of Unity 3D?
Creating a custom 12.04 CD with Ubuntu-2D as the default using Ubuntu-Builder
1. Get Ubuntu Builder and your source ISO
Ubuntu Builder automates many of the preliminary steps that had to be done by hand (mount ISO, extract squashfs, create chroot, etc.) It gives you Synaptic and a "graphical" chroot as well (Unity UI).
Download the latest version deb from here, and install with Software Centre or
dpkg -i
.Also download the Ubuntu Desktop ISO you're planning to work with.
2. Ubuntu Builder Basics
Start Ubuntu Builder from the Launcher. I recommend you set all three fields to "Ubuntu" (like the actual LiveCD), because setting custom fields led to Software Center crashing. When you install, you can choose your own username, machine name, etc. as always.
Load your ISO; I loaded the 64-bit with the Local Disk option, although Ubuntu Builder should be able to download the ISO if you want it to.
The buttons on the right are self-explanatory.
Console
gives you a CLI chroot, whileDesktop
gives you a graphical one!, i.e. a LiveCD session itself (this one may take a while to load). Note that theSelect DE/WM
does an incomplete job sometimes, so it's better to install via apt-get/Synaptic.3. Updating and setting Ubuntu 2D as the default
You can edit the
sources.list
with the button (or via the console) to add your own mirrors, ppas, etc; you can then update all packages withsudo apt-get update
andsudo apt-get (dist)upgrade
Set
ubuntu-2d
as the default shell: from the CLI chroot, run:4. Build, test and install!
Press the
Build
button in Ubuntu Builder to begin building the custom Live-CD ISO. UB automatically handles the cleanup, etc. that previously had to be done manually.The ISO can be found in
/home/ubuntu-builder
; you can test it using the built-in QEMU, or in another virtual machine.It can be "burned" to USB like the normal ISO, using Unetbootin (recommended), or
dd
.