Guides:
- https://stephentanner.com/restoring-grub-for-an-encrypted-lvm.html
- https://askubuntu.com/questions/719409/how-to-reinstall-grub-from-a-liveusb-if-the-partition-is-encrypted-and-there-i
- https://help.ubuntu.com/community/Grub2/Installing
cryptsetup luksOpen /dev/sdb3 sdb3_crypt
vgchange -ay
lvscan