Recently I attempted to convert CMG classic to a Virtual Scale Set using the native SCCM conversion option. The conversion failed and I had to reach out to Microsoft to help and support.
Per Microsoft, I was not the only one facing this challenge. I am sharing the actions undertaken to recover from failed conversion:
Problem: CMG went down after trying to upgrade from classic cloud to VSS to support the 2203 upgrade.
1. CMG showed error state and CMG connection point was disconnected in SCCM Console.
2. An attempt was made to remove the role from the site server and we reconfigured the CMG but it still failed as well.
3. It was observed that the Classic cloud upgraded to VSS on SCCM side but failed to provision the resources in Azure as there were only classic cloud and storage in the resource group.
4. For recovery of CMG, we reverted the SCCM to classic cloud deployment using the following query:
Update azure_service set Fqdn = ‘<CMG Service Name>’ , DeploymentModel = ‘1’
6. CMG role was reinstalled again on the server to take the changes into effect and it worked after 5 minutes.