Need to create a separate partition after installing Ubuntu

Question

I've already installed Ubuntu 12.04, but I did not make any separate partitions beside the one the operating system is installed on.

Now I want to make a new partition.

Is this possible?

Answer 1

Open gparted via a Live CD

Why live cd?

Gparted cannot modify mounted drives and since you only have 1 partition that means it's the one running Ubuntu. So you will have to open the live cd and do your edits from there.

What is a live CD?

live disc is a complete bootable computer operating system which runs in the computer's memory, rather than loading from the hard disk drive. It allows users to experience and evaluate an operating system without installing it or making any changes to the existing operating system on the computer

How-to

1. Back up your data before fiddling with partitions, just in case.
2. You will need to boot from the live cd (make sure to pick Try Ubuntu and not Install Ubuntu)
3. Open up gparted and choose to resize the current Linux partition
4. Shrink it from the end (not from the start; it sometimes causes problems)
5. Now that you have shrunk your partition, there will be some empty space at the end of the drive. Right click on it and pick format. Choose the filesystem and label for it
6. Press edit > apply all operations

Answer 2

If I understand (correct me if not) you installed Ubuntu to along all your 1TB HDD.

1. You should resize your primary partition (where are Ubuntu installed). The size of this new partition will be of the size that you want to. But remember that it will be limited and your system need have (I recommend you) more than 50GB.
2. Now you will have free space on your disk, this space must be formatted so that your system can use it. With the same program that you used for the resize (gparted) you can format that free space. How to do this:
   Secondary click on the new partition and choose format to. This should give you several options, choice to your preferences. For further information about this formats see Comparison of file systems.