FreeBSD mount at reboot

Question

In FreeBSD, how do I automate the process of mounting of a directory into a jail at boot time? Thank you.

Answer 1

How about using nullfs mounts? It's similar to bind-mounts on Linux. I.e. mount another location onto a folder.

Answer 2

Reading through /etc/default/rc.conf there are some nice entries for setting up jails. Most notable is:

#jail_example_exec_afterstart0="/bin/sh command"        # command to execute after the one for
                                                        # starting the jail. More than one can be
                                                        # specified using a trailing number

So you could use that to execute a script within the jail to mount a directory (as long as that directory is available from within the jail, such as NFS mounts etc).

Alternatively you would just ensure that the mounts are all done before the jail starts by using nullfs in /etc/fstab:

/path/to/source /path/to/jail/directory nullfs ro 0 0

Replace the ro with rw if you want to allow writing to that directory.