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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?

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up vote 2 down vote accepted

Steps taken from my more expansive answer on customizing a 12.04 LiveCD

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.

    enter image description here

  • 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, while Desktop gives you a graphical one!, i.e. a LiveCD session itself (this one may take a while to load). Note that the Select 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

Note: All this can also be done from Synaptic if you are more comfortable with that.

  • 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 with sudo apt-get update and sudo apt-get (dist)upgrade

  • Set ubuntu-2d as the default shell: from the CLI chroot, run:

    /usr/lib/lightdm/lightdm-set-defaults -s ubuntu-2d

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.

    enter image description here

  • 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.

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Thank you very much, I will test Ubuntu Builder for this purpose as soon as possible. Are there any additional configurations besides Unity 2D that this tool enables to perform, in order to make sure Ubuntu runs smoothly with, at least, its minimum requirements? I've tried Lubuntu before but there are some bugs while using the Live Session which do not happen with Ubuntu itself, so I'm looking for an Ubuntu version as light as possible. – Neptunno Jul 30 '12 at 2:17
Yes, you can configure anything with it, including Lubuntu -- you can download updates if they fix the bugs and put them on the LiveCD. See the original answer noted at the top for a more extensive tutorial (although thats about customizing with Gnome-2D (classic). – izx Jul 30 '12 at 2:36
I will, once again thanks! – Neptunno Jul 30 '12 at 2:39

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