Help debug my pine64A+ ubuntu/plex hangs

[MarkHaysHarris777]

I'm trying to understand why my pine64+ keeps hanging after 3 days or so ... when it became unreacheable from the network and I suspect the board hangs. How can I debug the problem? 
Any hint would be great.

One simple thing you can do is to setup a heart-beat monitor ( blinking LED ) on the system LED pins ; directly next to the IR port.  Use the code below:

sysled_heartbeat.sh

Code:

#!/bin/sh

echo $1  > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio$1/direction

COUNTER=0
while [ $COUNTER -lt 10 ]; do
   echo 0 > /sys/class/gpio/gpio$1/value
   sleep .35
   echo 1 > /sys/class/gpio/gpio$1/value
   sleep .65
done

echo $1  > /sys/class/gpio/unexport

You can run this code as sudo with :

      sudo  ./sysled_heartbeat.sh  359

This assumes you have the system LED plugged in;  the ballast resistor is built-in;  use a 3mm low power LED ( white is nice )

The idea is simple,  if the board hangs the light will stop blinking.  The blinking light requires the OS to be functional to provide the ON|OFF sleep cycles.

I suspect your board is NOT hanging ( the light will prove that ).  More likely your network connection has dropped for some reason... is this a wifi connection ?  If so, sometimes in idle states the wifi will shutdown to conserve power and the connection will drop.  Sometimes the eth connection will do the same;  one way to put a stop to this temporarily while you're getting a handle on the problem is to setup a script that wakes up once every few minutes to send three pings to your router ( use crontab ). Another thing you can do is to send part ( or all ) of your dmesg log to another machine using scp every so many minutes ( say thirty ). 

If your OS is hanging something is really wrong ( probably corrupted SD card ).  My PineA64+ boards ( both of them ) run 24-7-365 ... I rarely reboot them and they have both been running for several months now.  I have heart-beat monitors on all my boards, and I have a function monitor on my main server.