To monitor Hard disk health and logs in freebsd install smartmontools and enable smartd from /etc/rc.conf.
smartd.conf:
# The file gives a list of devices to monitor using smartd, with one
# device per line. Text after a hash (#) is ignored, and you may use
# spaces and tabs for white space. You may use ‘\’ to continue lines.
/dev/ad1 -s (S/../.././02|L/../../6/03) -m root@site.org
/dev/ad2 -s (S/../.././02|L/../../6/03) -m root@site.org