The next partition will be for root. However, the mount point will not be specified here, just the Size and “Use as” values. Knowing that a fresh installation of Ubuntu uses just 3.1 GB of disk space and just about the same for Linux Mint 16, I allocated 12 GB to it, which is sufficient to account for future increase in disk usage. For “Use as,” select “physical volume for encryption,” then type in the passphrase that will be used to encrypt the partition. OK.
Back to the main window again, you see an entry for the new partition (/dev/sda5) and also the encrypted volume create from it (/dev/mapper/sda5_crypt). Note also that no mount point is assigned by default. That will be done manually after all the partitions have been created. Select the free space and click on the + button to create the next partition.
This partition will be used for Swap, so I allocated just 2 GB (2000 MB) to it. From the “Use as” menu, select “physical volume for encryption,” then type in the passphrase. This is where this is different from the installer’s default disk encryption setup. And the minor inconvenience I wrote about earlier is that every partition will have it’s own disk encryption passphrase. What that means is that every time the computer is booted, you’ll have to type in the passphrase for each partition. So if you have three partitions, like the setup for this tutorial, that is how many times you’ll have to specify a passphrase. To make it easier, you can specify the same passphrase for the partitions. OK.
The final partition will be used for /home, so I allocated most of the available disk space to it. OK.
Back once again to the main window, you can see all the encrypted partitions that have been created. The final task at this stage involves assigning mount points. To do that, double-click on an encrypted partition entry.
This is the default “Edit partition” window. All that has to be modified here, is the “Mount point.”
For the root partition, it should be /.
for Swap, select “swap area.”
And /home for the last partition.
All set. you may click Install Now to continue with the rest of the installation.
On rebooting the computer after the installation has completed successfully, you will always be presented with the prompt shown in this screen shot, once for each encrypted partition that you created. That’s it for setting encrypted partitions manually on Ubuntu 13.10 and Linux Mint 16. If you want to set up a nuke passphrase for the partitions, see Apply the nuke patch to LUKS cryptsetup in Linux Mint 16 and Ubuntu 13.10.