Linux reboot and shutdown commands

This article describes basic uses for the shutdown command in Linux®.

Shutdown command

Use the shutdown command in Linux to shut down a device in a safe manner. You can modify the command
to notify users of the system shutdown, specify time arguments for the shutdown, and prevent any further
logins. Users must have root or sudo privileges to use shutdown. The command uses the following
structure:

shutdown [OPTIONS] [TIME] [MESSAGE]

Explanation of command elements:

• OPTIONS: Use OPTIONS to specify reboot, halt system, cancel request, display messages, and disable
  logins.

• TIMEe: Use TIME to specify a time argument to schedule a reboot at a specified time, schedule a reboot
  after a designated time, or specify an immediate shutdown.

• MESSAGE: Use MESSAGE to notify logged-in users of any specified message or instructions. Custom messages
  must follow a time argument.

The following example uses the shutdown command to begin the shutdown process. By default, this process
starts after a one-minute time interval.

[root@server-01 ~]# shutdown
Shutdown scheduled for Wed 2020-05-13 00:21:08 UTC, use 'shutdown -c' to cancel.

Specify a shutdown time

You can add a time argument in the following formats:

• hh:mm: Schedule a specific time.

• +m: Indicate the number of minutes until the shutdown.

The following example uses the hh:mm format to schedule a shutdown at 11:30 AM server time:

[root@server-01 ~]# shutdown 11:30
Shutdown scheduled for Wed 2020-05-13 11:30:00 UTC, use 'shutdown -c' to cancel.

The following example uses the +m format to schedule a shutdown in 30 minutes:

[root@server-01 ~]# shutdown +30
Shutdown scheduled for Wed 2020-05-13 01:03:13 UTC, use 'shutdown -c' to cancel.

The following examples use +0 or now for an immediate shutdown:

[root@server-01 ~]# shutdown +0
Shutdown scheduled for Wed 2020-05-13 00:48:11 UTC, use 'shutdown -c' to cancel.

[root@server-01 ~]# shutdown now

Add a custom shutdown message for logged-in users

Note: Remember that the custom message must follow a time argument.

The following example uses a custom wall message to display information about the shutdown to logged-in users:

[root@server-01 ~]# shutdown +5 "Shutdown in 5 Minutes for Updates"
Shutdown scheduled for Wed 2020-05-13 01:14:11 UTC, use 'shutdown -c' to cancel.

The following custom message displays to logged-in users:

Broadcast message from root@server-01 on pts/0 (Wed 2020-05-13 01:09:11 UTC):

Shutdown in 5 Minutes for Updates
The system is going down for poweroff at Wed 2020-05-13 01:14:11 UTC!

Reboot a system

You can use the -r option to initiate a reboot on the device instead of a shutdown.

The following example uses the reboot option to initiate a reboot:

[root@server-01 ~]# shutdown -r
Shutdown scheduled for Wed 2020-05-13 01:44:17 UTC, use 'shutdown -c' to cancel.

The following example uses the reboot option with a time argument and adds a custom message:

[root@server-01 ~]# shutdown -r  +10 "Rebooting in 10 Minutes for Updates"
Shutdown scheduled for Wed 2020-05-13 01:52:37 UTC, use 'shutdown -c' to cancel.

The following custom message displays to logged-in users:

Broadcast message from root@server-01 on pts/0 (Wed 2020-05-13 01:44:40 UTC):

Rebooting in 10 Minutes for Updates

The system is going down for reboot at Wed 2020-05-13 01:54:40 UTC!

Cancel a shutdown

You can use the -c option to cancel a scheduled shutdown.

The following example uses -c to cancel a scheduled shutdown:

[root@server-01 ~]# shutdown -c

The following system message displays to logged-in users:

Broadcast message from root@server-01 on pts/1 (Wed 2020-05-13 01:21:37 UTC):

The system shutdown has been cancelled