@mms I have one tip: do not use the normal mount or mount.fstab features when mounting stuff into the jail. It has a terrible failure mode if something is already mounted -- it will always error and prevent the jail from starting.

Instead do something like:

exec.prestart += "mount -a -F /etc/fstab.$name";

and

exec.poststop += "umount -a -F /etc/fstab.$name";


that will ensure the jail won't refuse to start if this happens.

I need to get this fixed upstream. It's a huge issue that somehow has been ignored for a long time.