NameResolution errors with B2 and Pihole for DNS

Hey gang, just wanted to drop a quick hint. On Feb 1st my duplicati backups started failing with
“Verifications”: [
“Key”: “”,
“Value”: [
“Key”: “Error”,
“Value”: “Error: NameResolutionFailure”
Turns out one of the adblock lists in pihole ( has flagged as malware and blocks requests to it. You’ll be able to test connections to B2, but you won’t be able to upload files to it.
It took me a bit to figure out what was going on so I thought I would just drop a quick post in case anyone else is having trouble.
Just whitelist and you should be good to go again.


Coincidentally, Backblaze B2 had DNS issues for everyone yesterday. I noticed a couple of my backup jobs failed with the same NameResolutionFailure for the B2 back end.