http://wiki.freebsd.org/HAST

gateN# mkdir /opt

gateN# cat /etc/hast.conf

resource r0 {
        on gate1 {
                local /dev/ad1
                remote 10.0.0.2
        }
        on gate2 {
                local /dev/ad1
                remote 10.0.0.1
        }
}

gateN# cat /etc/rc.conf
...
hastd_enable=yes

gateN# /etc/rc.d/hastd start

gateN# hastctl create r0

gate1# hastctl role primary r0

gate2# hastctl role secondary r0

gateN# hastctl status

gate1# newfs /dev/hast/r0

gate1# mount /dev/hast/r0 /opt

gate1# umount /opt

gate1# hastctl role secondary r0

gate2# hastctl role primary r0

gate2# fsck -y -t ufs /dev/hast/r0

gate2# mount /dev/hast/r0 /opt

gate2# umount /opt

gate2# hastctl role secondary r0

Выбираем узел, данные которого будут затерты.

gateZ# hastctl create r0

gateZ# hastctl role secondary r0

gateZ# hastctl status

gateM# hastctl status