Is it possible to enlarge cgd-encrypted partition?

[Eugene Andrienko <evg.andrienko%gmail.com@localhost>]

Hello! I'm planning a disk configuration for my home NAS and stuck with
the subject. Maybe someone already have the experience or an expertise
to be able to say is a next thing possible or not?
Sadly, I didn't found (or didn't understood) the answer while reading
The Guide and man pages.

The existing system description:

1) I have a disk #1 with a big partition (rraid0b) used as a physical
   volume for a volume group (vg0), for LVM.
2) On top of vg0 there is a logical volume lv0, which takes all
   available space on the rraid0b.
3) On top of the lv0 there will be encrypted CGD device. The resulting
   cgd0a will be formatted in FFSv2.

What I'm trying to achieve:

4) Buy a big disk #2 and add it to the volume group vg0 with the help of
   lvm vgextend command. Then enlarge the logical volume lv0 to the size
   at near rraid0b_size + big_disk_no2_size (with the help of lvm
   lvextend command).
5) ??? do something with cgd ???
6) Enlarge FFSv2 with the help of resize_ffs command.
7) Don't lost my files during the process.

And the question is for the item #5: what to do with the CGD device? If
the size of underlying device (lv0) was increased, will it be possible
to simply resize FFSv2 on the cgd0a to the new size?

Or some unknown for me commands are necessary to enlarge the cgd device
after lv0 size was increased?

-- 
Eugene Andrienko