These are just notes
/srv/jail/base-RELENG_7_2/root contains the read-only base tree, with initial seed packages /srv/jail/paka/root is the chroot basedir /srv/jail/paka/persist is the rw union dir, to persist changes across invocations
mount -t nullfs -o ro /srv/jail/base-RELENG_7_2/root /srv/jail/paka/root mount -t unionfs -o noatime /srv/jail/paka/persist /srv/jail/paka/root mount -t nullfs -o ro /usr/srcs /srv/jail/paka/root/usr/srcs
jail_enable="NO" # Jail defaults jail_devfs_enable="YES" jail_exec_start="/bin/sh /etc/rc" jail_exec_stop="/bin/sh /etc/rc.shutdown" # Jails jail_list="paka" jail_paka_rootdir="/srv/jail/paka/root" jail_paka_hostname="paka" jail_paka_ip="127.44.0.1" jail_paka_exec_prestart0="mount -t nullfs -o ro /srv/jail/base-RELENG_7_2/root /srv/jail/paka/root" jail_paka_exec_prestart1="mount -t unionfs -o noatime /srv/jail/paka/persist /srv/jail/paka/root" jail_paka_exec_prestart2="mount -t nullfs -o ro /usr/srcs /srv/jail/paka/root/usr/srcs" jail_paka_exec_poststop0="umount -f /srv/jail/paka/root/usr/srcs" jail_paka_exec_poststop1="umount -f /srv/jail/paka/root" jail_paka_exec_poststop2="umount -f /srv/jail/paka/root"