In today's practical tutorial I am going to teach you the correct way to resize partitions de Linux active and running such as that of our Ubuntu operating system, in this case Ubuntu 13.04.
One of the most cumbersome things that Linux has against compared to Windows, is not being able to resize partitions on a hard disk or partition of a system that is in use, the reason is that in order to do this process we will first have to unmount the volume to resize.
As I tell you in the heading of the tutorial, this is a big disadvantage compared to Windows since from its native tool disk management We can resize the volume of the unit in use, which is the one that has the operating system installed Microsoft, without having to disassemble the volume of the unit and in just a few minutes.
In Linux we can also do this process, the only thing is that we will have to do it from a Live CD o Ubuntu Live USB; in this case we will do it from Live USB from Ubuntu 13.04 that we created in a previous exercise using Yumi.
The first thing we should do is restart our system with the Live USB de Ubuntu 13.04 and from the Bios options select the pendrive to be the first boot option, once the USB is started and on the main Yumi screen we will select Linux distributions and then the option to test Ubuntu 13.04 without installing on the hard drive.

Once we are shown the Ubuntu desktop We can now follow the steps that I describe step by step below.
Steps to follow to resize partitions
Once started from the Live distro we will go to the dash and type gparted:

We click on the icon and the main window of the program will appear gparted which is a utility for managing disk drives.

As you can see in the screenshot above, I have two partitions created, one for Windows 8 and another for Ubuntu 13.04, we will select the Linux partition that is in format EXT and hovering over it we will click on the right button of the mouse to select the option of Resize / Move.

Now a new window appears from which we will modify the selected partition without damaging the hosted operating system, in this case Ubuntu 13.04.

We can resize the Linux partition directly entering the new size in the text boxes or use the top bar by moving left or right.
When we finish assigning the new dimension, we will only have to click on the button Resize / Move and wait very patiently for the process to finish, a process that can take several hours.
With this we will have resized our partition of Linux, nothing complicated although quite tedious and cumbersome.