by iceguy » 09 Sep 2015, 21:52
I doubt that power flickers are the cause of the GUI dying.
I own quite a few 1500 Amp-hr UPS's. I put one behind my home theater/audio system and plugged the RPi B+/HifiBerry into it along with my satellite receiver, the WiFi network router, and my Sony TV into that unit. The UPS told me that it could run hours with that load.
I reflashed the memory for RPi B+/HifiBerry and went through the rather tedious setup procedure. I tested runeaudio and found that it all worked fine.
The next night I was watching satellite TV when the line AC went out for a full second and then came back. There was no interruption on the TV, though my Onkyo receiver handling the audio clicked off. Then the line AC then went out and returned twice more in quick succession. Again the TV and video signal went right on.
Using my web browser on my smartphone, I checked the GUI and found that it was working fine! Clearly it had survived the three power outages. After restarting the audio receiver, I could play music from my NAS -- on a similar UPS in another room -- without difficulty. Clearly the UPS kept the RPi setup running through the power outage.
For a couple of weeks I used the RPi B+/HifiBerry DAC through the rune GUI, but one day I opened the GUI from my smartphone and it didn't work anymore. While it could see the RPi B+/HifiBerry DAC, I could not get it to add music to the queue, whether I tried to do it from a playlist or from the library itself. I checked the NAS and it was running fine.
The GUI was locked up.
So the problem is not just power related. I suspect that it occurs when I leave the GUI connected to some browser on a machine that goes to sleep, and then try to re-access it from another browser on another machine.
Also, this time, I ssh-ed in to the RPi as root and issued a "shutdown -r now" to reboot. After a few minutes, I could ping the RPi B+/DAC at the same static IP address I had given it during the last setup. However, the GUI was not up and wouldn't start. Neither could I ssh in. Clearly the ssh daemon was not up and running.
It would be nice to be able to restart the system in this circumstance, rather than reflashing and going through the setup, but I suspect that rune does not include the commands to start the appropriate daemons on boot, including those that bring up ssh and the web server to restart the GUI, typically found down some path like /etc/rc.d/init.d.