How do I schedule a reboot on Linux?

Question

I'd like to be able to schedule a server reboot at a specific time, but not regularly. How can I do this without futzing with adding and removing cron entries?

Answer 1

If it is one-time deal, you can use shutdown command with -r as argument. Instead of using shutdown now, you can add time as parameter. Example:

shutdown -r 12:30

This also works with times in the early morning - so if it's 15:55 now, you can reboot the server at 3:15am tomorrow morning. You can also add & to put the command in background so you can log-off without killing the shutdown command. Example:

shutdown -r 03:15 &

In case, to cancel that reboot: run this:

shutdown -c

Answer 2

According to the man page: /sbin/shutdown [-t sec] [-arkhncfFHP] time [warning-message] found at --> http://unixhelp.ed.ac.uk/CGI/man-cgi?shutdown+8

Load of options to choose from but, to answer your question.

To reboot in 5 minutes: /sbin/shutdown -r 5 "reboot in five minutes"

To reboot at exactly 11:00 P.M.: /sbin/shutdown -r 23:00 "rebooting at 11:00 P.M."

NOTE: your message will be broadcast to all active terminals / sessions.

Answer 3

the at command is what you want.

at 5:00pm 
do
cd /
/full/path/to/init 6
done

at -l will list the at cmds

Answer 4

The easiest way I can think of is:

# sleep 2h && reboot

Run this as root.

Answer 5

echo "reboot" | at -m 23:00       

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