Log into another encrypted linux system using a LiveCD

gistfile1.txt

# if you want to use a non qwerty keyboard layout
sudo dpkg-reconfigure keyboard-configuration

sudo cryptsetup luksOpen /dev/sda3 some-vg
# enter password
sudo vgscan

# mount the root drive
sudo mount /dev/mapper/some--vg-root /mnt
# consult /mnt/etc/fstab to find out where the boot directories are so you can mount them
exec sudo su -
cd /mnt
cat etc/fstab
mount /dev/path/from/fstab boot
mount /dev/path/from/fstab boot/EFI/
mount -t proc proc proc/
mount -t sysfs sys sys/
mount -o bind /dev dev/
chroot . /bin/bash