Why /home should be on a different partition than /

Nirbheek had advised me to always keep /home on a separate partition, and it came in handy today.

Introduction

Natty Narwhal is the new Ubuntu release made on 28th of April, 2011. When I tried to upgrade to it yesterday, bad things happened.

While the installation went smoothly up to the step Installing the upgrades, it simply hung after trying to Load lirc module on my HP dv2000 laptop. More so, my laptop became unresponsive. The next step I took (I do not know why I did it), was to open a terminal and type:

sudo reboot

The Problem


This was a really bad idea, as it turned out.

The next time I tried to log on, I was greeted with the unfriendly error:

Kernel crash while updating to Natty Narwhal

5 cm per second

Sometime ago, Nirbheek recommended me a anime movie which I watched and liked a lot.
It was named 5 centimeters per second and it is currently my favorite anime movie of all times. Quoting from Wikipedia:

The title 5 Centimeters Per Second comes from the speed at which cherry blossoms (also called Sakura blossoms) petals fall, petals being a metaphorical representation of humans, reminiscent of the slowness of life and how people often start together but slowly drift into their separate ways

And I remember this fact from the movie well. Also, I was until very recently, in Japan and I missed the Sakura blossoms (and the calamity) by a whisker (about 3 weeks).