The WHM panel provides two options for a server reboot:
- Forceful Server Reboot
- Graceful Server Reboot
The recommended option is Graceful Reboot. This way the reboot will be queued, and when all services are stopped the server will be restarted.
In a case there is a very high load on the server, the Graceful Reboot might not be sufficient. Then you will need to use the Forceful Server Reboot option.