You may receive a cPanel & WHM update failure notification with the following:
The cPanel & WHM update process failed for the following reason:
Maintenance ended; however, it did not exit cleanly (256). The following events were logged: /scripts/check_unreliable_resolvers. Review the update logs to determine why the update failed.
This notification is sent when the script
/scripts/check_unreliable_resolvers found that some, or all, of the configured DNS servers, are not reachable from your server. You can find the DNS servers configured on your server in
/etc/resolv.conf or WHM >> Resolver Configuration.
To find which DNS server is unreachable, you can run the following script:
(Note: the output has been truncated for visibility)
⚠ Partial DNS resolver failure
Once you have found which DNS servers are unreachable, you can temporarily disable them by adding a '#' to the front of each unreachable DNS server line in
Optionally, you can use WHM >> Resolver Configuration to remove the unreachable DNS servers, or to add new DNS servers that are reachable from your server.
If all DNS servers are failing, you can temporarily use Google's public DNS servers 184.108.40.206 and 220.127.116.11, however, please use your hosting provider or internet service providers' DNS servers when possible. Using public DNS servers may cause RBL's such as Spamhaus to not function correctly.
Our documentation on Resolver Configuration can be found here.