> What is deleting your journal?  It's not named doing that.
Hm.
Maybe this
	destroy_chroot() {
		cp -af ${CHROOT}/namedb/master/*.signed /opt/etc/named/namedb/master/
should be
	destroy_chroot() {
		cp -af ${CHROOT}/namedb/master/*.{jnl,signed} /opt/etc/named/namedb/master/
?