All you need to know is found here http://deb.riseup.net/storage/encryption/dmcrypt/
Comments
- Stock debian 2.6 kernel works just fine
- Stock debian kernel is modular - so looking in /proc/crypto before you start won't show aes, and dmsetup targets won't show crypto
- Here - I'm adding an lvm2 partition for this (the comments at the end of the above link about lvm are about putting lvm pv's onto a crypt partition - here I have a crypt partition on top of lvm - so the comments do not apply)