The bastille convert sub-command will convert a thin jail to a thick jail if only the TARGET argument is given.
If a TARGET and RELEASE is specified, it will convert the jail into a custom release. The jail will remain intact, and you will have a duplicate of it to use a a release base for any new jails.
EXAMPLES
Convert myjail from thin to thick:
# bastille convert myjail
Create myrelease from myjail:
# bastille convert myjail myrelease