How do I attempt to find out why my computer didn't wake up from sleep/crashed?

[bassamanator]

Every so often I find that my computer doesn’t wake up from sleep. The fans/LEDs turn on but my screens remain blank. SYSKEY also doesn’t work. I suspect that my swapfile isn’t large enough but I don’t know (I have 16GiB of memory and a 10GiB swapfile which I will be increasing in size shortly).

How do I attempt to find out what happened?

Thanks!

[mbb]

Hi!

First of all, if the kind of sleep you’re talking about is a suspend and not an hibernate, you don’t need a swapfile. So, is this suspending or hibernating?

Second, 10GB would only be insufficient if you were using way more than that, since hibernation compresses the data stored on disk. Besides this, when the system can’t hibernate or suspend, it just comes back after some seconds with a black screen. So I doubt the problem is lack of swap space.

Finally, to know what’s going on you use journalctl searching for errors from the previous boot:

journalctl -p3 -b-1

[bassamanator]

It’s sleeping and not hibernating.

So I ended up increasing the swap space to 16GiB just for the heck of it. I have no idea if that made a difference because this problems crops up only occasionally, I would say once every 2 weeks (I put my computer to sleep at night).

Thanks for that command, I’ll use it if I have a crash again.