Linux systems generally require very few reboots for reliability and availability. Generally, kernel updates or critical library updates require a reboot. Linux provides the reboot command in order to restart the system. We can use reboot , shutdown and systemctl commands in order to reboot a Linux system or server.
Reboot Linux
Most Linux distributions provide the reboot command in order to reboot or restart the Linux system. The reboot command is located in the /sbin/reboot . We can call the reboot command directly like below.
$ rebootAlternatively, if the bash environment is not set properly or if there is a problem to call the reboot command we can use its full path which is standard in most Linux distributions.
$ /sbin/rebootSome distributions are more secure and require root privileges to reboot the system. A regular user can not reboot the system unless using the sudo command. In the following example, we reboot the system using the sudo command.
$ sudo rebootReboot Linux Using “shutdown” Command
All Linux distributions provide the shutdown command in order to shutdown or reboot the system. Even it is named as shutdown we can use it to reboot or restart the system. We provide -r option to the shutdown command in order to reboot the system.
$ shutdown -rReboot Linux Using “systemctl reboot” Command
The systemctl command is created to manage Linux services and run levels. But the systemctl command can be also used to reboot a Linux system. The reboot parameter is provided to the systemctl command like below to restart the system.
$ sudo systemctl rebootReboot After Specified Wait Time
We can set a wait time before the restart of the system. The shutdown command is provided with the -r option and +2 to wait 2 minutes.
$ sudo shutdown -r +2Reboot Remote Server or System
We can also reboot remote servers or systems using the reboot command. We use the ssh command to call remote server reboot command like below.
$ ssh [email protected] rebootReboot and Start BIOS
BIOS is the hardware simple operating system used to initialize the system hardware. When a system is started or restarted first the BIOS is loaded and then an actual operating system like Linux is started. We can reboot the system and start the BIOS screen using the systemctl command.
$ sudo systemctl reboot --firmware-setup