NAME
rc.shutdown —
    command script run at system
    shutdown
DESCRIPTION
When the system is shut down using the reboot(8) or halt(8) commands, or when init(8) is signalled to do so, or when a keyboard-requested halt is issued (if the architecture supports it), rc(8) is invoked with the argument “shutdown”. This document details the actions taken by rc(8) in such an instance.
Firstly it saves random data for reseeding the kernel random
    number generator during the next boot. It then stops any daemons defined in
    the pkg_scripts variable in
    rc.conf.local(8), as well as
    vmd(8), in that
    order, by passing them the stop argument.
rc(8)
    then runs rc.shutdown. The administrator should
    place in this file any commands they wish to have executed during
  shutdown.
Finally, all carp(4) interfaces are brought down and then the system shuts down.
If init(8) is exiting single-user mode it will also run the first part of shutdown (saving random data), though not the latter.
FILES
- /etc/rc.shutdown
 - Command script run at system shutdown.
 - /etc/examples/rc.shutdown
 - Example script.