Every post I see here is either a laptop, or somebody who restarted their computer whilst asleep mid-upgrade. My case is neither.

So I started a release upgrade from 14.04 to 15.10, some 10 hours ago. around 30 minutes into it, my monitor went to sleep. Neither moving the mouse or hitting any key on the keyboard has any effect, however the computer is still running.

10 hours is a bit past the high side for how long an upgrade takes, Would it be slower if it's running in sleep mode? When, if ever will it be safe to hold the power down and force a reboot?

Please advise.