Failed to reboot system via logind: Interactive authentication required.
1. reboot failed

deepnorth@deepnorth-amax:~$ reboot
Failed to set wall message, ignoring: Interactive authentication required.
Failed to reboot system via logind: Interactive authentication required.
Failed to start reboot.target: Interactive authentication required.
See system logs and 'systemctl status reboot.target' for details.
Failed to open /dev/initctl: Permission denied
Failed to talk to init daemon.
deepnorth@deepnorth-amax:~$
deepnorth@deepnorth-amax:~$ sudo reboot

2. sudo reboot

daemon [ˈdiːmən]：n. Guardian processes, background programs