http://www.freebsd.org/doc/en_US.ISO8859-1/articles/gjournal-desktop/configure-journal.html

[Manolis Kiagias]

Andrei Tanasescu wrote:
> Hello,
>
> The procedure is incomplete, and will fail every time. Before enabling journaling, the user should issue swapoff on the future journaling partitions.
>
> Thanks_______________________________________________
>
>   
This is mentioned in section 3.2 of the article (Booting for the first
time):


"Your system will come up normally, but you will need to edit /etc/fstab
and remove the extra swap partitions you created for the journals.
Normally, the swap partition you will actually use is the one with the
“b” suffix (i.e. ad0s1b in our example). Remove all other swap space
entries and reboot so that FreeBSD will stop using them."