I've installed 5.6 on a system that I am trying to run as a background server. Periodically, it looks like the system goes into hibernation or sleep (not a laptop). I've checked the BIOS for any power settings (there are none), and tried disabling all of the power saving features found in settings -> power manager. I'm wondering if there is somewhere else I need to disable something?
I'm still trying to pinpoint the exact circumstances that see the hibernation. I'm seeing the issue after I move it into it's final location. It's working fine after the initial boot (and if I keep an active connection to it, it's been up for hours), but if I disconnect and leave it it drops off the network completely (port is down on the switch) which makes me think it's full hibernation.