Change Passphrase for encrypted root Volume (Ubuntu / LVM / dm-crypt)

Here’s a quick list of handling the passwords / passphrases for an encrypted disk:

• get to know which is the device name (e.g. /dev/sda2)
• list keys:

sudo cryptsetup luksDump /dev/sdXY

• add a key:

sudo cryptsetup luksAddKey /dev/sdXY

• remove a key:

sudo cryptsetup luksRemoveKey /dev/sdXY

• see also:
  • Full disk encryption with Ubuntu (9.04 Jaunty or newer), LVM and LUKS
  • How to change the password of a encrypted LVM system (done with the alternate Installation)?