Resizing a External HD without losing data? [duplicate]

(Step 0:) Back up anything really valuable. This is a pretty tried and tested formula but things can go wrong. A power cut at the wrong moment could really ruin your day if you haven't backed up.

  1. Boot to a LiveCD or LiveUSB drive in "try me" mode.
  2. Load gparted (should be installed by default, you can apt-get it if it's not)
  3. Resize your partitions (right click, click resize, follow the instructions).
  4. Click apply and sit back while it does the job.
  5. Reboot, taking out the USB stick or CD when it tells you to.

If you have already installed Ubuntu 12.04, then install GParted with sudo apt-get install gparted.

Launch it using Alt+F2, and typing gparted.

In order to expand the 63GB partition, you must have unallocated space adjacent right to this partition. So first you will have to use GParted to resize a partition above or below your 63GB partition. Refer the following figure:

A GParted session

When you click on resize, a window will open where you can easily drag and resize your partition. Once the free space is made available, resize your 63GB partition just like the above covering that free space.


You can only re-partition unmounted partitions.

I have a gParted live disc ready for things like that. You can find it here: http://gparted.sourceforge.net/livecd.php

Basic features:

GParted enables you to easily manage your disk partitions:

  • Create partition tables, (e.g., msdos or gpt)
  • Create, move, copy, resize, check, label, set new UUID, and delete partitions
  • Enable and disable partition flags, (e.g., boot or hidden)
  • Align partitions to mebibyte (MiB) or traditional cylinder boundaries
  • Attempt data rescue from lost partitions

Resizing is explained in the documentation of gParted. In short (the link has some extra information and tips):

Resizing and moving a partition can be performed by a single gparted operation. To resize a partition:

  • Select an unmounted partition. See the section called “Selecting a Partition”.

  • Choose: Partition → Resize/Move. The application displays the Resize/Move /path-to-partition dialog.

  • Adjust the size of the partition. See the section called “Specifying Partition Size and Location”.

  • Specify the alignment of the partition. See the section called “Specifying Partition Alignment”.

  • Click Resize/Move.


One way that you can shrink partitions without losing data is by using GParted. A very good application, but be careful with it.

Edit: Boot from a live CD so you will be able to do the resizing. Install gparted with Ubuntu Software center, or any other way (synaptic etc) you prefer, if it isn't already installed.

It will ask you to authenticate when you run it, as it has access to things that can damage your installation badly. Realise that by altering partitions on your hard drive(s) you can potentially stop your system booting completely. As I said, be careful.

It will then search devices it can see and display the partitions on the first one (probably /dev/sda, if not try different devices from the pull down at the top right). You should be able to see that one of them contains your root (/) mount point. When you are sure you have the correct one (the size itself is a good indicator), right-click on that partition and choose Resize/Move (if it is greyed out, you might need to unmount it first (make sure you have booted off a live CD, and not your installed linux system). Reduce the size in the middle (New Size) edit box to what you want (make sure it's still large enough for your system's needs). Click on resize/move, then use the big green tick to apply the changes. If it reports success, then should be able to shutdown the live cd and reboot into your main system.

Edit2: I just googled a tutorial you might look at gpart tutorial