[linux] reboot和shutdown-r的区别

google看看：

先搜英文的资料

http://askubuntu.com/questions/441969/what-is-the-difference-between-reboot-and-shutdown-r

(ubuntu论坛)

结论是：reboot uses shutdown -r

http://unix.stackexchange.com/questions/64280/what-is-the-difference-between-reboot-init-6-and-shutdown-r-now

(好像讨论的是linux问题)

结论是：reboot uses the shutdown command (with the -r switch).

再搜索中文的资料

http://bbs.chinaunix.net/forum.php?mod=viewthread&tid=1383005&highlight=reboot%2Bshutdown%2B-r

(freebsd论坛)

结论是：reboot命令重启动系统时是删除所有的进程，而不是平稳地终止它们

先看下freebsd 9.3

root@93a:~ # man reboot
REBOOT()               FreeBSD System Manager's Manual              REBOOT(8)
DESCRIPTION
     The halt and reboot utilities flush the file system cache to disk, send
     all running processes a SIGTERM (and subsequently a SIGKILL) and, respec-
     tively, halt or restart the system.  The action is logged, including
     entering a shutdown record into the user accounting database.

root@93b:~ # man shutdown
SHUTDOWN()             FreeBSD System Manager's Manual            SHUTDOWN(8)
DESCRIPTION
     The shutdown utility provides an automated shutdown procedure for super-
     users to nicely notify users when the system is shutting down, saving
     them from system administrators, hackers, and gurus, who would otherwise
     not bother with such niceties.

     -r      The system is rebooted at the specified time.

本人英文较烂，按自己的翻译能力得知：

reboot过程会把系统的缓存写到硬盘，先发送SIGTERM再发送SIGKILL；

shutdown过程友好地通知线上用户，然后完好地保存。

结论即是：reboot与shutdown -r过程一致

下面是自己实际操作的结果

很明显reboot没有出现deamon平稳地终止过程，这是闹哪样啊。

顺便看下centos 6.7

[root@vhost102 ~]# man reboot
DESCRIPTION
       These programs allow a system administrator to reboot, halt or poweroff the system.

       When  called with --force or when in runlevel  or , this tool invokes the reboot() system call itself and directly reboots the system.  Otherwise this simply invokes the shutdown()
       tool with the appropriate arguments.

       Before invoking reboot(), a shutdown time record is first written to /var/log/wtmp

[root@vhost102 ~]# man shutdown
DESCRIPTION
       shutdown arranges for the system to be brought down in a safe way.  All logged-in users are notified that the system is going down and, within the last five minutes of TIME, new logins
       are prevented.
OPTIONS
       -r     Requests that the system be rebooted after it has been brought down.

reboot --force 调用reboot重启系统，否则调用适当的shutdown参数

shutdown会安全地关机

结论即是：reboot与shutdown -r过程一致

reboot的过程

shutdown -r now的过程

总结一个吧

freebsd 9.3 reoot与shutdwon -r now不一致，reoot没有平稳地终止服务强制重启。

centos 6.7 reoot与shutdwon -r now一致，两者都是平稳地终止服务后重启。