This tutorial presents a step-by-step guide on how to configure full disk encryption manually on Ubuntu 13.10 and Linux Mint 16. It will also work for any other Ubuntu-based distribution, like Linux Deepin.
The point of setting up encrypted partitions manually is so that you can create more than the two default partitions (root and swap) created by Ubiquity, Ubuntu’s graphical installation program, when the automated disk partitioning mode is used and the LVM and disk encryption options are selected. And also to be able to do that when attempting to set up a dual-boot system between, say, Ubuntu or Linux Mint and Windows 7 or Windows 8. The automated partitioning mode does allow using LVM and disk encryption when setting up a dual-boot system.
The problem is that even the manual step doesn’t work as well as it is supposed to, as you’ll see later in this tutorial.
Before we start, let’s take a look at the default partitions and logical volumes that the installer creates when LVM and disk encryption are selected. This screen shot, which was taken from a test installation of Netrunner, shows those partitions and logical volumes. You can see that the first partition – /dev/sda1, mounted at /boot, is a standard partition. The second partition – /dev/sda5, is a logical partition. It is that logical partition that the installer uses to create the LVM Physical Volume. Under that Physical Volume, the installer then created the encrypted Logical Volumes for LVM. You can see the Logical Volumes listed at the top section of the image.
For this tutorial, we are going to create a separate encrypted partition for /home. It is not absolutely necessary, but it’s always nice to have /home in a separate partition. This screen shot just shows the installation requirements for Ubuntu 13.10. You can see that the recommended disk space (for Ubuntu 13.10) is 5.9 GB. The actual disk space used by a fresh installation of this edition of Ubuntu is 3.2 GB. That should give you an idea of how much disk space to allocate to the root partition.
That ends the introduction. Let’s get to the real thing. The test system used for this was a guest OS in a virtual environment, and 100 GB of disk space was allocated to it. The goal is to create manual partitions, with a standard partition mounted at /boot and three encrypted partitions, one each for root, home and Swap. Note that because of the manner the graphical installer works, LVM cannot be configured manually. So this tutorial has nothing to do with LVM, just full disk encryption. It creates a minor inconvenience that we’ll see later in this tutorial.
Ok, boot the computer from the installation media that I’m sure you have created by now and start the installer. Click until you get to the “Installation type” step. Since we want to create our partitions manually, the option to select is Something else.
Selecting Something else and clicking Continue should take you to the installer’s Advanced Partitioning Tool’s window.
This is the Advanced Partitioning Tool’s window. On a system with existing partitions, there should a listing of those partitions here. If that’s the case with your system, delete them. If you have another OS that you wish to dual-boot with Ubuntu or Linux Mint, then make sure that you have free space sufficient for installing either distribution. Since the system I used has a brand new disk, it is first necessary to create a partition table before partitions can be created from it. To do that, select the disk as shown and click on the New Partition Table button.
Now that a partition table has been created, select the free space and click on the + button. That should open the partition creation window.
And this is what that window looks like. For a standalone installation, the most important options to change here, are Size, Use as, and Mount point.
For the first partition, which will be for the boot partition, I chose to use the same value for Size and “Use as” that is assigned to it by the automated installer. And the “Mount point” is, of course, /boot. OK.
Back to the main window, select the free space, then click on the + button to create the next partition.