I have installed Ubuntu on an external usb drive. I have no internal HDD in the laptop. Have installed ubuntu from live DVD and after installation, it worked very well.
However once I shut down (restarted) the system since I was asked to after all the updates, the laptop does not switch on. It shows the VAIO at the begining and then it is just black screen. The BIOS is capable of booting from external device and I have enabled the feature.
This is my first time using Ubuntu. I have Ubuntu 12.04 and the HDD is a 2.5" USB 3.0, 500 GB (without external power source) from Toshiba.