If you work with a product for a long time, you would start loving it. I have worked with many other RDBMS, but my love to SQL Server will never die. The amount of information available in logs is very helpful and can help in pointing the exact issue related to retrieve data.
One of my clients was installing Service Pack on a clustered SQL instance and it was failing. I looked into Detail.txt and found below information.
2017-02-28 11:03:44 Slp: Running Action: RunDiscoveryAction
2017-02-28 11:03:44 Slp: Running discovery on local machine
2017-02-28 11:03:47 Slp: Discovery on local machine is complete
2017-02-28 11:03:47 Slp: Running discovery on remote machine: SQLNODE-B
2017-02-28 11:05:21 Slp: Discovery on SQLNODE-B failed due to exception
2017-02-28 11:05:21 Slp: Microsoft.SqlServer.Management.Sdk.Sfc.EnumeratorException: Failed to retrieve data for this request. —> Microsoft.SqlServer.Configuration.Sco.SqlRegistryException: The network path was not found.
Based on my understanding of .net, the stack goes from bottom to top. If we look at functions called, it looks like a Registry call to get details from remote nodes. It seems that in order to complete the remote discovery, setup has to read the registry of the remote node. We attempted to open the registry on node SQLNODE-B from registry editor on node SQLNODE-A. (Start > run > Regedit)
As soon as we gave the remote node name, it failed to open the registry and gave the same error.
We realized that “Remote Registry” service was “Disabled” on remote node. Enabling that, solved the problem.
Reference: Pinal Dave (http://blog.SQLAuthority.com)