[systemd-devel] systemctl reboot/halt with non-privilege user

[Simon McVittie]

On Wed, 28 Oct 2020 at 14:11:07 +0200, Mantas Mikulėnas wrote:
> I'm not entirely sure why reboot is treated differently from halt, though.

If you reboot a machine, it will (hopefully!) come back up after some
downtime, so it's a limited level of denial of service and might make sense
to restrict a little less than poweroff and halt.

If you power off a machine, someone needs to go and press the power button
to bring it back up (unless you have proper server infrastructure with
remote-power-cycle capabilities), so it's a stronger denial-of-service
if this happens on a remote machine.

If you halt a machine, it will halt the OS kernel and hang (not fully
powered-off, still consuming power) which in my experience is rarely what
you actually wanted, but the practical impact is similar to poweroff.

    smcv