DNS/DHCP server is not working after a restart

[AtHirsizi]

First of all, i may be wrong about describing technical terms below. I'm still confused and lost about all the happening.

Everything is kind of messed up on my Pi after a restart. Let me explain the situation:

I'm using Pi-Hole as a DNS/DHCP server for the last 2 years. It's 192.168.0.12. On my network i have 6 devices using it. They have all 192.168.0.12 (aka Pi-hole) as primary and only DNS server.

The thing is, after a necessary restart about an hour ago, all devices failed to access Pi-hole. All wi-fi icons turned into "no connection".

Funny thing is, somehow my phone is connected to the ruined Pi-hole and wi-fi icon is on. But it only recieves WhatsApp, Twitter and some news app notifications. (I assume they are using other ports than 80, 81 and 443). All TCP/UDP services are not working.

I can't access Pi-hole web interface, also SSH connection via PuTTy. I am going to mount a keyboard and a monitor to the Pi as a last resort.

What should i look at and do after connecting peripherals to the Pi?

Thanks in advance.

[jfb]

@AtHirsizi

What should i look at and do after connecting peripherals to the Pi?

Please send us the token generated by

pihole -d

or do it through the Web interface:

How do I debug my Pi-hole installation?

Method 1: Generate a debug token via the Web interface Log in to your Pi-hole's Web interface Navigate to Tools > Generate debug log Click the Generate debug log button Send us the debug token [debug] Method 2: Use the command line to generate a debug token Login into your Pi-hole's command line Enter pihole -d Provide us with the debug token that is generated after the debug script completes Alternative: Securely sending us additional information Preferred Method If there is additi…

[AtHirsizi]

Oh FFS. The whole thing was caused by removing the external HDD while restarting the Pi.

I removed it for copying some stuff from Pi to Windows, but totally forgot i did this a while ago:

sudo mount -t auto /dev/sda1 /media/USBHDD1

So it seems when poor little Pi can't find the external HDD it lost his mind and created a mini crisis. After i plugged the HDD back into Pi, it is up and working again!