I'm running a system (Fedora 27) which often freezes completely when I've been away from the computer for a while. As I am running computation in the background, I can tell that the freeze happens anywhere from minutes to hours after I've locked the computer. The computer is running, but is otherwise completely unresponsive (screen doesn't turn on, num lock on keyboard does nothing, etc).
Where would I start to debug this? What log files might help me figure out what the problem is? The computer never freezes while I'm working at it, which obviously makes me suspect that it's related to GDM turning the screen off,but I'm unable to find other people with similar problems.