Unknown error on Pi-hole

Creating a bug report/issue

Hi All,
My Pi-hole started showing an unknown error message when I want to see the query log. I can’t find a solution so I’d like some help. I’m running this server on a Raspberry Pi 4, on DietPi v8.8.1 OS.
I took a couple of screenshots about the issue:
Screenshot 1
Screenshot 2
Screenshot 3

Required Information

  • Distro version | bullseye 0
  • Kernel version | Linux MediaServer 5.15.61-v8+ #1579 SMP PREEMPT Fri Aug 26 11:16:44 BST 2022 aarch64 GNU/Linux
  • SBC model | RPi 4 Model B (aarch64)

Additional Information (if applicable)

  • Software title | Pi-hole

  • Was the software title installed freshly or updated/migrated?
    Fresh install

  • Can this issue be replicated on a fresh installation of DietPi?

  • Bug report ID | 7f86b7f5-e07f-464f-a296-64ae49134e90

Hello, can you post the output of:

ss -tulpn | grep :53

This checks if another service (e.g. dnsmasq) is listening on port 53 and prevent pihole-ftl from working.

I guess issue is inside PiHole application and not with the DNS server in genral. Maybe a problems with query database. You could try to delete the current db file and let PiHole create a new fresh one

Hi! This is the output:

root@MediaServer:~# ss -tulpn | grep :53
udp   UNCONN 0      0               *    users:(("unbound",pid=887,fd=3))                                                                                               
udp   UNCONN 0      0               *    users:(("java",pid=5180,fd=189))                                                                                               
udp   UNCONN 0      0               *    users:(("java",pid=5180,fd=183))                                                                                               
udp   UNCONN 0      0               *    users:(("java",pid=5180,fd=182))                                                                                               
udp   UNCONN 0      0               *    users:(("java",pid=5180,fd=181))                                                                                               
udp   UNCONN 0      0               *    users:(("java",pid=5180,fd=180))                                                                                               
udp   UNCONN 0      0               *    users:(("systemd-resolve",pid=594,fd=11))                                                                                      
udp   UNCONN 0      0            *    users:(("Plex Media Serv",pid=4873,fd=99))                                                                                     
udp   UNCONN 0      0             *    users:(("pihole-FTL",pid=1150,fd=8))                                                                                           
udp   UNCONN 0      0           *    users:(("pihole-FTL",pid=1150,fd=6))                                                                                           
udp   UNCONN 0      0               *    users:(("connectd",pid=893,fd=5))                                                                                              
udp   UNCONN 0      0                               *:5355             *:*    users:(("systemd-resolve",pid=594,fd=13))                                                                                      
tcp   LISTEN 0      4096            *    users:(("systemd-resolve",pid=594,fd=12))                                                                                      
tcp   LISTEN 0      32            *    users:(("pihole-FTL",pid=1150,fd=9))                                                                                           
tcp   LISTEN 0      32          *    users:(("pihole-FTL",pid=1150,fd=7))                                                                                           
tcp   LISTEN 0      256             *    users:(("unbound",pid=887,fd=4))                                                                                               
tcp   LISTEN 0      4096                         [::]:5355          [::]:*    users:(("systemd-resolve",pid=594,fd=14))

I asked help from Pi-hole support and they directed me here, because I use Dietpi… How can I delete the current db?

The db is at /etc/pihole/pihole-FTL.db and can be removed with

rm /etc/pihole/pihole-FTL.db

Yeah don’t forget to stop PiHole FTL service before.

Could you link the post from PiHole forum?

Thank you! I was able to remove the pihole-FTL.db. Let’s see what happens next!

Of course! This is a Reddit link.

Did you generate the Debug log for the PiHole guys as they requested on Reddit? I see this request open for 25 days but somehow no answers from your side.

Also check /var/log/pihole.log and /var/log/pihole-FTL.log for entries right after triggering the error.

Also, can you scroll the error message at the web UI? If so, probably there is some more meaningful line at the end.

Since they have redirected me to the Dietpi forum, I didn’t followed the post anymore. I have deleted the pihole-FTL.db and then started Pi-Hole again, I’m still experiencing the same thing. I’ve scrolled down in the error message window and there was no useful information.

Could you explain where exactly the issue happens? For me this is something inside the PiHole application and I’m not 100% sure how we could fix it from our side. You could try to perform a reinstall. Maybe there is an issue on the PiHole scripts that could be fixed by performing a reinstall.

It happens when I go inside long term data, then Query Log and when I Select date and time range and select a range… Sometimes I don’t get this error message, but most often I do.
I have reinstalled Pi-Hole now, set it as a DHCP server and unchecked Conditional forwarding, checked DNSSEC validation. Since that error occurred randomly, I let Pi-Hole to work for a bit and test it again. Thank you for trying to help me!

Do the log files I posted above show any related entries? Check them shortly after you faced the issue.

And so check:

dmesg -l emerg,alert,crit,err

Thank you for your help! Since I reinstalled Pi-Hole (<24 hrs ago), I don’t get this unknown error message.
For dmesg -l emerg,alert,crit,err

  • I get the following:
[    2.627142] sd 1:0:0:0: [sdc] No Caching mode page found
[    2.627154] sd 1:0:0:0: [sdc] Assuming drive cache: write through

These has been always present on my system.

Probably some issues on PiHole files that hopefully got fixed due to reinstall.