Graceful reboot means to shut down all services gracefully, allowing currently running operations to finish, then reboot. Normally, whenever a system initiates a reboot, the system brings down in a safe and secure way.
Steps to gracefully reboot the server
Step 1:login to the Ovi ACP.
Step 2:Click on the graceful reboot module in the ACP.
Step 3:To reboot the server click on soft reboot button it will take some time to completely reboot the server.
Step 4:If you want to go back to the ACP click on Goto ACP button.
For more information kindly refer the below Video tutorial