Recently set up root encryption with a couple of LVM volumes inside one LUKS volume, and I am just a little confused as to how I would go about getting it to automatically unlock using a keyfile stored on a USB flash drive, I presume I would have to put the drive in the fstab inside my initramfs (if there is one), and add a hook for USB device support.

But I digress, essentially, I want to know what I have to do to enable my LUKS volume (containing all of my partitions sans /boot) to unlock using a keyfile stored on a USB flash drive, rather than a manually entered passphrase.