How to Install Ubuntu11.04 on Mac mini

This guide will explain how to install Ubuntu 11.04 on an external USB HDD.

1. Download and install rEFIt under OSX.
2. Insert Ubuntu Installation CD to an external USB CD drive.
3. Reboot and hold Alt key to boot from the CD drive.
4. Before installing Ubuntu, press F6 and select each options except the last one.
Some options, noapci nopic nomodeset, should be turned off otherwise Linux will halt during the installation.There options would be disabled as well after the installation.

5. Install Ubuntu on the USB HDD drive and do remember to install grub on the USB HDD as well.
6. After the first reboot of installation, rEFIt should detect Linux.
7. Choice to boot from Linux, GRUB will be loaded.
8. Press "E" to edit boot options of GRUB.
Find and add options to Linux boot arguments:

linux /boot/vmlinuz-2.6.32-24-generic \
root=UUID=xxxx-xxx-xxx-xxxx ro quiet \
nosplash noapci nopci nomodeset reboot=apci

Press Ctrl+X to boot Ubuntu after the modification.

9. Install NVIDIA proprietary driver to enable 3D/OpenGL.
10. Enjoy Ubuntu 11.04.