吃完飯回來發現虛擬機死了，強制退出後重啓出現如下現象：
***An error occured during the filesystem check
***Dropping you to a shell; the system will reboot
***when you leave the shell.
......
Give root password for maintainence
(or type Controll-D to continue)
查閱資料之後
輸入Root用戶的PW之後，輸入FSCK命令，輸入"y"
最後Reboot
重啓正常