Installing ubunto on an encrypted lvm partition is easy using the ubuntu alternate cd.

However, accessing your data in case of emergency using a life cd needs some additional steps

1. Boot from live cd

sudo modprobe dm-crypt                      # Inserts a module we need
sudo cryptsetup luksOpen /dev/sda2 cheer   # Unlocks the partition sda2 and names it cheer
Enter LUKS passphrase: 
key slot 0 unlocked.
sudo apt-get install lvm2  # installs the tools we need
sudo modprobe dm-mod       # inserts a module we need
sudo vgscan                # Scans for all volume groups
  Reading all physical volumes.  This may take a while...
  Found volume group "Ubuntu" using metadata type lvm2
sudo vgchange -a y Ubuntu  # this made the VG Ubuntu active, if you don't give it a volume group as an argument it'll make them  all active        
sudo lvscan                # This command lists the logical volumes and their /dev path
  ACTIVE            '/dev/Ubuntu/Root' [15.00 GB] inherit
  ACTIVE            '/dev/Ubuntu/swap' [1.00 GB] inherit
  ACTIVE            '/dev/Ubuntu/home' [215.89 GB] inherit
#
# Now I mount them to do whatever it is I need to do, if you wanted to run a fsck on them you obviously wouldn't mount them.
#
sudo mkdir /media/root; sudo mkdir /media/home
sudo mount /dev/Ubuntu/Root /media/root; sudo mount /dev/Ubuntu/home /media/home
#
# Now to reverse the process and unmount everything
#
sudo umount /media/root; sudo umount /media/home
sudo rmdir /media/root; sudo rmdir /media/home
sudo vgchange -a n Ubuntu 
sudo cryptsetup luksClose cheer

~~LINKBACK~~