proxmox3.4

Hello, I have a problem upgrading proxmox 3.4 to 4.4 on VPS server. i used this howto https://pve.proxmox.com/wiki/Upgrade_from_3.x_to_4.0. Every thing went well, even the step apt-get dist-upgrade without error. After that they ask for reboot. my server didn't reboot. This happend to me...