Automounting secondary LUKS encrypted disc in Ubuntu

Tutorial on ASK Ubuntu.com - Mount LUKS encrypted hard drive at boot.

Basic concept:

1. Prepare a new keyfile
2. Add the keyfile to cryptsetup
3. Set the disc in /etc/crypttab (create the mapper)
4. Set the disc in /etc/fstab (use that mapper)

Datailed instructions:

1. sudo su
2. dd if=/dev/urandom of=/home/myusername/.keyfiles/mydisk bs=1024 count=4
   (location should be on another encrypted storage!)
3. record could be in the form:
   mydisk UUID=15bd5643-675c-4985-b7ab-33c40c46dde3 /home/myusername/.keyfiles/mydisk nofail
   Could be set with gnome-disk-utility

ll /dev/disk/by-uuid

https://wiki.archlinux.org/index.php/dm-crypt/Device_encryption

https://askubuntu.com/questions/450895/mount-luks-encrypted-hard-drive-at-boot

lubuntu, http://www.porteus.org/component/content/article/26-tutorials/general-info-tutorials/114-official-porteus-installation-guide.html#USB-linux

https://www.techradar.com/news/best-lightweight-linux-distro