Backing up an encrypted partition

[vittorio]

From time to time I backup up my ad0s3a and ad0s3d partitions by means of dump 
issuing a 'dump -a0f  fileA /dev/ad0s3a' etc.

Having just set up a gdbe encrypted partition /dev/ads0s3e which I mount with

gbde attach /dev/ad0s3e -l /etc/gbde/ad0s3e
mount /dev/ad0s3e.bde /mydir/encrypt

I wonder WHAT should I now dump when backing up:

dump -a0f  fileE /dev/ad0s3e

OR

dump -a0f  fileE /dev/ad0s3e.bde

?

Ciao
Vittorio