illumos gate

Currently, fs-minimal has the following code:

for fs in /var /var/adm /tmp; do
        readvfstab $fs < $vfstab
        if [ -n "$mountp" ]; then
                mounted $mountp $mntopts $fstype < /etc/mnttab && continue
                checkfs $fsckdev $fstype $mountp || exit $SMF_EXIT_ERR_FATAL
                mountfs -O $mountp $fstype $mntopts - ||
                    exit $SMF_EXIT_ERR_FATAL
                continue
        fi
        if [ "$rootiszfs" = 1 ]; then
                mountpt=`zfs get -H -o value mountpoint $be$fs 2>/dev/null`
                if [ $? = 0 ] ; then
                        if [ "x$mountpt" = "x$fs" ] ; then
                                /sbin/zfs mount -O $be$fs
                        fi
                fi
        fi
done

If /var is a separate FS, which is a part of BE and you previously mounted BE to some temporary location, on the next boot to this BE /var will not be mounted,
as its mountpoint will be set to something like '/mnt/var' and not '/var'.
The possible fix could look like this:

for fs in /var /var/adm /tmp; do
        readvfstab $fs < $vfstab
        if [ -n "$mountp" ]; then
                mounted $mountp $mntopts $fstype < /etc/mnttab && continue
                checkfs $fsckdev $fstype $mountp || exit $SMF_EXIT_ERR_FATAL
                mountfs -O $mountp $fstype $mntopts - ||
                    exit $SMF_EXIT_ERR_FATAL
                continue
        fi
        if [ "$rootiszfs" = 1 ]; then
                mountpt=`zfs get -H -o value mountpoint $be$fs 2>/dev/null`
                if [ $? = 0 ] ; then
                        if [ "x$mountpt" != "x$fs" ] ; then
                              /sbin/zfs set mountpoint=$fs $be$fs
                        fi
                        /sbin/zfs mount -O $be$fs                       
                fi
        fi
done