正確的關機

1. Linux 為多人多工環境，螢幕背後可能有多人或多個服務正在工作，不正常關機可能造成檔案系統毀損。
2. who：查看誰在線上。
   

   [root@dywHome2 ~]# who
   dywang   tty1         2008-09-07 06:00
   

3. shutdown：通知線上使用者關機的時刻後關機。
   

   [root@mdk-dyw ~]# shutdown
   Usage:    shutdown [-akrhfnc] [-t secs] time [warning message]
                     -a:      use /etc/shutdown.allow
                     -k:      don't really shutdown, only warn.
                     -r:      reboot after shutdown.
                     -h:      halt after shutdown.
                     -f:      do a 'fast' reboot (skip fsck).
                     -F:      Force fsck on reboot.
                     -n:      do not go through "init" but go down real fast.
                     -c:      cancel a running shutdown.
                     -t secs: delay between warning and kill signal.
                     ** the "time" argument is mandatory! (try "now") **
   [root@mdk-dyw ~]# shutdown -h now
   [root@mdk-dyw ~]# shutdown -h 00:05
   [root@mdk-dyw ~]# shutdown -h +30
   [root@mdk-dyw ~]# shutdown -r now
   [root@mdk-dyw ~]# shutdown -r +30 'The system will reboot'
   [root@mdk-dyw ~]# shutdown -k now 'This system will reboot'
   

4. halt：關機。
   

   [root@mdk-dyw ~]# halt
   

5. reboot：重新開機。
   

   [root@mdk-dyw ~]# reboot