Shutting down the Linux systems can be done in different ways. We can use provided GUI like KDE, GNOME, Unity ect. to shutdown system. But what will we do if we have only console access to the system. We can use shutdown command to shutdown and reboot system.

Syntax

shutdown [OPTIONS...] [TIME] [MESSAGE...]

Shutdown System

We can use shutdown command without providing any option or parameter to simply shutdown the system. We need required privileges like root to shutdown a linux system.

$ shutdown

Shutdown At Specified Time

Sometimes we need more time before shutting down the system. We can provide some interval before the shutdown command take effect with the time value

In this example we will shutdown the system after 5 minutes now.

$shutdown -h 5

Restart System

We can restart the Linux system with shutdown command. This will first shutdown system and then restart. We should provide -r option which means restart.

$shutdown -r

Restart At Specified Time

We can also restart the system at specified time. We will use -r option again by adding the interval value we want to wait. In this example we want to restart the system after 10 minutes.

$ shutdown -r 10

Skip File System Check (fsck) at Reboot

Linux operating systems generally check a file system at start if there is some problems. This file system check may take some time. We can skip this file system check with -f option.

$ shutdown -r -f

Send Message To System Users

Linux operating system is designed to work multi user. At given time there may be more than one user connected to the Linux system. Shutting down will interrupt their connection and work too. We can send some message with shutdown command. As stated in syntax the message it the last part of the shutdown command.

In this example we will send message This system will shutdown in 5 minutes

$shutdown 5 "This system will shutdown in 5 minutes"

Reboot System

We have alternative command to reboot the Linux system. We can simply use reboot command for this.

$ reboot

Permissions For Reboot

In Linux system root is the highest privileged administrator account. In order to reboot or shutdown we need root privileges. If we try to reboot without this privileges we will get errors like following.

Failed to set wall message, ignoring: Interactive authentication required.
Failed to reboot system via logind: Interactive authentication required.
Failed to open /dev/initctl: Permission denied
Failed to talk to init daemon.

LEARN MORE How To Shutdown Linux System?

So we have provide root privileges with the sudo command like below.

$ sudo reboot

Linux Shutdown and Reboot Command Tutorial with Examples