Hey everyone I have noticed over the last little while my HA on raspberry pi just dies. I have to physically reboot the pi and everything comes back just fine. After the reboot I get this message in my log then everything boots fine.
I thought maybe the timestamp would point to somthing in thr historu but nothing happend around 4:40am. The stange thing is that even after the system stops responding the history still keeps track. Also ehen it goes down I lose everything ssh,samba. I am thinking maybe nic or maybe my router is killing the connection or somthing.
2018-01-15 20:04:27 WARNING (Recorder) [homeassistant.components.recorder] Ended unfinished session (id=21 from 2018-01-14 04:40:35.325371)
I came here to say the same thing. My Pi has gone down, I can tell remotely (I’m at work). Automations stop working, samba share stops working (so I can’t check the log files over the network), can’t access the front end locally, but I can still ping it and get a response.
Seems to happen at random. It had 3 weeks uptime, then as of it dying today, it was less than 12hrs uptime.
Mine does this, It will disappear from the network (Attached to router with Lan cable) and is unresponsive until I pull the power and reboot. SSH does not work until rebooted.
This appears to be random and no logs after rebooting to diagnose with.
This might be due to some power-saving settings of the pi.
I had the problem with a pi zero w, was a little different since the interface was wireless, but the behaviour were similar.
I think mine might be related to size of my config now, found a long message today about time out of sync. I dont think I have an overly complicated config though. 10 light switches, 3 bulbs, 3 plugs and a few other things.
I seem to have more stability lately (v 0.60.0 plus) But mine has been doing the same thing.
Using official Pi Power Supply and noobs card…
Like @touliloup I also had this kind of problems with a PiZero and after switching to a Pi3 I haven’t got any problems.
Its been running Hass.io since firsts beta’s came out and it is running Mosquitto broker (which is heavily used by me and also share it with my family members outside my home network), PiHole, AppDaemon, Mopidy, Snapcast and a few other addons and my configuration is very extensive with alot of components, automations and scripts and the SDCard 16gb it’s been running 24/7 for at least 2 years now.
The only difference I can tell is the the restart time isn’t as fast as it used to be (but still nothing compared to the PiZero!!!).
I play with the idea to limit the memory for home-assistant on low system. So that one container can’t eat the resource of others 
I just upgraded to 0.61.1 I was on 0.60.0 so will see what that brings. I was having some issues with my Yeelight stuff so maybe that was beating on the pi a bit to much. those have been resolved now.