How do I reboot a Ubuntu Server from the command line? sudo reboot now never seems to work for me. Because its a server, I don't have a window manager installed, so I can't do it from a GUI (which always seems to work).

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I've had the problem for years on different versions of the operating system. It happens in virtual machines and on real metal. The same problem exists with sudo shutdown now, too.

I've lived with it in the past. The difference now is I don't want to just hit the power button because I might lose data.

  • Have you tried sudo shutdown -r now ? Dec 30, 2013 at 4:25
  • 4
    sudo reboot now is not a valid option. see man 8 reboot
    – sourav c.
    Dec 30, 2013 at 4:31
  • Thanks souravc - that's interesting. The command never complains about an invalid option. I'll test some of these when I get out of mysql.
    – user207039
    Dec 30, 2013 at 4:45
  • 4
    sudo init 6 must always work. Also, there are Ctrl+Alt+Del and REISUB.
    – Danatela
    Dec 30, 2013 at 5:46

5 Answers 5


Try using the following command to safely reboot:

sudo reboot

If, instead, you want to shut down the server safely, use this command:

sudo shutdown -h now
  • 2
    You did not mention "safely" in the sudo reboot method, it may mislead some users.
    – rap-2-h
    Jan 15, 2018 at 8:53
  • @rap-2-h Wait, so do you mean sudo reboot is safe or not safe?
    – wisbucky
    May 3, 2018 at 20:16
  • @wisbucky : sudo reboot is safe
    – Jay
    May 10, 2018 at 4:05
  • had a debate with a coworker about this today. Is this method preferred over sudo poweroff?
    – Gansheim
    Jul 24, 2018 at 6:10

For reboot, type the following

sudo shutdown -r now

As an alternative to sudo shutdown -r now, this command also effects an immediate shut-down:

sudo shutdown -h +0

Add the -r command to reboot:

sudo shutdown -r -h +0

Output (running as root):

root@mydevwkstn:~# shutdown -r -h +0

Broadcast message from cjbs@mydevwkstn
        (/dev/pts/10) at 14:41 ...

The system is going down for halt NOW!

An alternate way:

sudo init 6


Without the init program there could be no command interpreter process.


If you want to reboot your system, using @Jay's solution, you'll notice that the reboot will be scheduled by one minute. If, instead, you want your system to reboot immediately, you can use the following command:

reboot -f

The -f parameter will force your reboot to happen as soon as you enter the command.

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