This was really helpful to me, and I succeeded in adding an encrypted physical volume while running under Ubuntu 10.04. However, there are a few things I would like to contribute that might help the next person reading this article. The arguments "lvm=vg0-root,lvm=vg0" from the line added to cryptroot do not seem to be correct as far as I can tell. The correct syntax is "lvm=/dev/mapper/vgname-lvname" where vgname is the volume group name and lvname is the logical volume name. In the scenario described above you only need ONE per line, not TWO. Eg Give "lvm=XXX", not "lvm=XXX,lvm=YYY" on a single line of cryptroot. Since I couldn't find the syntax of cryptroot documented anywhere, I went to the source to figure out the syntax: /usr/share/initramfs-tools/scripts/local-top. [Developers can read methods activate_vg(), setup_mapping(), and parse_options() for details ] The target variable contains the name of the device file created in /dev/mapper that is associated with the decrypted physical volume. So "target=pvcrypt0" results in the file /dev/mapper/pvcrypt0, which you can then use in a command such as "vgextend vg0 /dev/mapper/pvcrypt0". The source variable can also be used with UUIDs: "source=UUID=ENTER_YOUR_UUID_VALUE_HERE" You might want to create a backup of your initrd files prior to running "update-initramfs" if you aren't 100% sure of what you're doing. Backup the files returned by "ls /boot/initrd.img-*". Note that the file /etc/initramfs-tools/conf.d/cryptroot may not already exist, so just create it.