Pi-hole should keep running and running and running
Actual Behaviour:
Every now and then Pi-hole is no longer reachable from within my network. I usually find out about this because there is no internet connection on an Apple device. (side note Android devices seem less prone to this issue)
I use the Android app 'RasPi check' to do basic monitoring and the occasional reboot. The pi is usually no longer reachable on the app when this happens.
This happens sometimes 2-3 times per day and on other times not for 4 weeks. So very random.
My Set-up is the following
Pi-hole is installed on a raspberry pi Zero W
power supply comes from the USB port of my FRITZ!Box Fon WLAN 7390
a USB dongle (no brand) is providing a LAN port and I have connected the lan cable to my fritzbox port
there are no other USB devices connected to the pi
there is no screen or keyboard connected to the pi
I have tried to connect the times when the pi stops working with other events but so far I was not able to make any sense.
e.g. One or many devices accessing the network, additional load on the Fritzbox (there is none that I'm aware of), time of day
Could this be a pi hole power issue? I have heard that there a funny things happening when there is not enough power but I simply don't know how to debug this.
This is not a recommended source of power. There is no standard for power on a USB port. The Pi may run, but perhaps not well and not without damage to the SD card.
Buy a proper power supply of adequate rating for that Pi model.
I know that this is not a stand alone power supply. As I've mentioned the pi runs fine for most of the time all the time. Therefore I'm wondering if I can pinpoint the issues to the power.
I have not spare power socket where the fritzbox is and I would like to avoid re-working my set-up unless I have to.
Do you have multiple AVM products in a Mesh configuration? There is a known bug (this usually also involves switches between the Mesh devices) where some devices aren't reachable anymore in your network. One typically doesn't notice this issue, however, with the DNS server you always notice it because it basically means the network is down.
It is a confirmed issue by AVM support, they're working on a fix but (apparently) don't yet know how to solve the issue. The best advise they have right now is removing any "indirect cabling" between the devices and to connect all devices directly to the Mesh Master.
There s a pretty long discussion about this in German (if it is the same problem):
