FreeBSD启动出错，无法挂载其他目录

ERROR: ABORTING BOOT (sending SIGTERM to parent)!
Jan 00:52:25 init: /bin/sh on /etc/rc terminated abnormally, going to single user mode
Enter full pathname of shell or RETURN for /bin/sh:

按回车后运行：

 /sbin/fsck -y /dev/ad0s1a