问一个很简单的问题

leaonlew

reboot 和shutdow -ry 0有什么区别？

camham

应该是使用shutdown好一些,可以正常关闭系统进程(init守护的).
不确定

leaonlew

据了解shutdown是正常关闭行程，而reboot只是kill进程，shutdown　－ry 0的安全性高

eee_fish

shutdown -ry 0
虽然也是立刻从新启动，但是这条命令仍然会正常的关闭进程，正常卸栽文件系统，正常执行用户自定义的关机脚本（例如关闭数据库等）。
reboot
立刻使用kill -9杀死所有运行进程，把文件系统标为干净的，然后立刻启动。所以有可能造成文件系统出现问题，数据库系统的不正常关闭，用户数据的丢失等。所以建议不要在多用户下使用该命令。

朽木可雕

The shutdown Command Details
Executing the shutdown command stops system activities in an orderly and consistent
manner. The shutdown command performs the following tasks:
• Prompts the administrator for a broadcast message to send to all users.
• Broadcasts the warning message to all user terminal sessions.
• Grants a 60 second (by default) grace period for users to log out.
• Kills all user logins.
• Shuts down all non-critical processes.
• Unmounts all non-critical file systems.
Depending on the option specified, shutdown will either leave the system in single-user mode
(no options), the halt state (if -h was specified), or initiate a reboot (if -r was specified).
Common shutdown options:
# shutdown -hy 600 # shutdown to a halt state in 600 seconds.
# "-y" (yes) option prevents shutdown from
# requesting confirmation before proceeding.
# shutdown -ry 600 # reboot in 600 seconds without requesting confirmation.
# shutdown -ry 0 # reboot immediately without requesting confirmation.

Reboot Command Details
The reboot command uses "kill -9" to kill running processes,
quickly, but can cause problems for applications and file
shuts down applications and processes more gracefully,
halting or rebooting the system from multi-user mode.
The system is already in single-user mode.
You need to bring the system down very quickly.

leaonlew

good

cqwlyh

任何情况下，都建议管理员使用shutdown来关机或重新启动，原因有两方面：
1. shutdown会调用init来“安全”的关闭所有的进程，而reboot只是强行kill它找到的任何进程。
2. 如果修改了kernel，用reboot重新启动，系统是不会rebuilding内核的。