There are tons of guides online for creating jails, and an always excellent page in the handbook, but precious few instructions for deleting them.

Assuming you used ezjail with default settings, you can blow them all away with this:

# echo "WARNING, THIS WILL DELETE ALL OF THEM!"
# chflags -R noschg /usr/jails
# rm -rf /usr/jails

Then you can start over again; as opposed to just starting again, or starting over. I remember noschg by thinking of Benedict Reuschling :).

Wait, I don’t think I’ve ever posted about using jails here, or ezjail, or even iocage. Making a mental and physical note to correct this.