Since the Ubuntu 12.04 LTS the hibernate icon disappeared as possible option at the shutdown. It is not a big loss if you are not used to use (or overuse) it as I often do. Personally I think that the hibernate feature is really useful when you want to freeze your computer maintaining all the windows -and the work- you are working on at a precise moment. 

Ubuntu decided to “cut” this particular command from its GUI because it registered a remarkable number of problems caused by hardware conflicts in modern computers. 

If you use Ubuntu and you think that hibernate could till be useful for you (especially during busy working days), it is possible to insert again this specific feature as GUI on your Desktop.

First of all you have to test if your computer contains the right hardware for “hibernate” so open Terminal and type:

sudo pm-hibernate

The computer will hibernate itself but you have to reboot it to understand if hibernate worked properly in your case.

I hope (as it was for my PC) that all has gone well. In this case you can start to create the dedicated icon on your upper bar.

Before of starting it’s necessary to understand that the hibernate command will use the SWAP partition to save your temporarily data. Usually it is recommended to have a SWAP partition with, at least, the double of space of your RAM.

So I suggest to install Gparted to check the SWAP space and, only if necessary, increase your SWAP partition reducing the primary partition. Please, do this only after you safely backup all the data in your computer because this procedure could be risky if you are doing it for the first time and you have not enough experience:

sudo apt-get install gparted

Open a Terminal and install gedit and gksu (if you don’t have them already installed on your machine) typing:

sudo apt-get install gksu && sudo apt-get install gedit

sudo gksu gedit /etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla

Copy and paste the following text to “compile” it:

[Enable Hibernate]

Identity=unix-user:*

Action=org.freedesktop.upower.hibernate

ResultActive=yes

Save it and reboot your computer.

A new icon will appear on the right corner of the upper bar. When you click on it, a Terminal window will appear asking for the system password. Type it and click on Return and your PC will immediately hibernate. 

Good busy working days!