How to create separate /home partition when using full disk encryption feature in the Ubuntu 12.10 installer?
Warning: Keep in mind what you are doing has to be done right or you may potentially destroy other systems on your hard drive or data on other partitions. If you are installing to the entire hard drive and want to overwrite the entire disk, no worries.
When you are installing, when you see this screen:
Choose Something else.
You will need to create the minimum of two partitions (three if you want a swap).
Create one partition for you system and set it's mount point to '/'
Create another partition for your home directory and set it's mount point to '/home'
Create a swap partition as well if you need one.
When you are asked to encrypt the /home directory, choose that option.
See this tutorial before you start this process. If you have another system installed already and want it to install beside it, make sure you back it up with remastersys or just back up your files.
This works on Mint 17.2 as well. It's hard to believe this still hasn't been fixed.
Boot to install disk, and open terminal. Assuming you want to use GPT, without UEFI, partition your disk with gdisk.
Now create the LUKS container on the partition you just created, and call it "lvm" (or whatever you want):
Create the physical volume for LVM in the LUKS container, and then the volume group:
Create your logical volumes (your sizes may vary):
Now start the installer, leaving the terminal open. At the partitioning step, select "Something Else". Set the mount points for the following, checking the "format" box where applicable:
Now continue installation, but at the end of the installation click "Continue trying."
Back in your terminal, mount your new system in a chroot:
Edit or create /etc/crypttab, with the following line:
your UUID will be different, of course. This will cause the system to try to open the LUKS container at boot, with the name "lvm".
It's the initial RAM image that will actually do this, so we need to update it:
This will read from the crypttab file and make the necessary changes to the initram image. Now you'll get a prompt to enter your passphrase at boot.
Unmount everything, just to be safe:
Now reboot, and remove the install disk.
So here's what happens at boot:
Here's a good reference.