...(Read EXAMPLE.md for the system installation example)...
This is a partially-automated version of Naldi Stefano's tutorial, which was partly based on blog posts by Pavel Kogan here and here. Also, the original script that is avilable here. All credit goes to them for figuring out how to do it. I edited and tested it with the BTRFS+SWAP setup (no LVM here, unneeded when you use BTRFS). There are benefits of this setup such as:
- BTRFS snapshots
- Timeshift can be used to make snapshots instead of RSYNC
- timeshift-autosnap-apt script can be used to take BTRFS snapshots of your system right before removing/upgrading packages
- grub-btrfs script can be used to make GRUB boot your system from the snapshots
The Linux Mint 21.3 installer (codename: Virginia) has an option for installing on LVM inside
an encrypted LUKS container, but this is only offered if you want to erase
the whole disk (no dual boot), and also leaves the /boot partition
unencrypted. If you want to encrypt everything including /boot
you have to configure the bootloader and initramfs manually -- which is
time-consuming and easy to get wrong. This script guides you through the
process, and automates as many of the commands as possible, making it much
easier to set up.
This is still an advanced configuration, though, and assumes you are comfortable with the terminal, shell scripts, partitioning, and installing and managing normal non-encrypted Linux systems. If in doubt, read the tutorial linked above, and above all, PLEASE BE CAREFUL. Typing anything wrong here could erase your hard drive! Make sure you test anything in a virtual machine before trying it on your real machine.
I also suggest that you do not use it against the drives where the existing OSes are installed (unless, until you practice with the script and know how to use it before that). It is better to practice inside a virtual machine before doing it on a real system.
Boot the Linux Mint 21.3 live USB as normal. But instead of running the 'Install Linux Mint' launcher on the desktop, open a terminal and run the following commands:
sudo apt-get -y install git
git clone https://github.com/calliecameron/mint-encrypted-install
cd mint-encrypted-install
./mint-encrypted-install.sh
This will guide you through the rest of the process.