how to create an encrypted ext3 filesystem using "cryptsetup"?

[Robert P. J. Day]

   one of those things for which the docs are tantalizingly incomplete -- 
what is the minimal amount of work i need to do to simply create and mount 
an encrypted ext3 filesystem on FC2?

   as a start, i installed using LVM2, creating a single volume group 
"vol0".  so, to create an encrypted filesystem, i first added a new LV 
with:

   # lvcreate --size 1G --name crypt vol0

which correctly created the new files:

   /dev/vol0/crypt -> /dev/mapper/vol0-crypt

so far, so good.

   at this point, based on the docs, i would run "cryptsetup", but there's 
no incantation i've tried that works.  there's no man page for cryptsetup, 
and everything i try comes back with:

   # cryptsetup ...
   Command failed: invalid argument.

not overly helpful. :-P

   (by the way, given that "aes" is the default cipher, i figured out
quickly that i needed to "modprobe aes" first.)

   so ... what's the rest of the recipe to get my encrypted FS?

rday