Normally, the shutdown command is used and recommended for rebooting the system on your web hosting. This command will give users advance warning so that they can save their work and cleanly terminating specific programs. The syntax is as following:
shutdown -r time "message"
-r : Reboot the system.
time : When to reboot. You can reboot immediately or after 2 minutes. It can be an absolute time in the format hh:mm, in which hh is the hour (1 or 2 digits) and mm is the minute of the hour (in wo digits). Second, it can be in the format +m, in which m is the number of minutes to wait. The word now is an alias for +0.
message: Send warning message to send to all users.
Steps to reboot the system
Use the following command to reboot system immediate as root user:
shutdown -r now
shutdown -r +0
Task: Reboot with warning message (recommended)
To reboot system in 5 minutes with the following warning message:
shutdown -r +5 "Server is going down for kernel upgrade. Please save your work ASAP."