The command to reboot a linux server is reboot, but there are several things you should know before you start rebooting.
Permissions Required to Reboot
The linux user must either be root, belong to the wheel group, or have sudo permission. If you typically use sudo, then just prefix all the reboot commands below with sudo, for example:
sudo reboot
Reboot Command Options
Depending on your operating system reboot may support different options. You can run man reboot to find out which options your linux operating system supports. You may also try reboot --help to see which reboot options are available.
Reboot Options on Ubuntu 24.04 and 22.04
Here is the result of reboot --help on Ubuntu 24.04 server, the result is the same as 22.04
reboot [OPTIONS...] [ARG]
Reboot the system.
Options:
--help Show this help
--halt Halt the machine
-p --poweroff Switch off the machine
--reboot Reboot the machine
-f --force Force immediate halt/power-off/reboot
-w --wtmp-only Don't halt/power-off/reboot, just write wtmp record
-d --no-wtmp Don't write wtmp record
--no-wall Don't send wall message before halt/power-off/reboot
Reboot the Linux Server Now
To reboot the linux server right now you could use the -f or --force flags:
reboot --force