Troubleshoot Azure extension for SQL Server deployment
Applies to: 
SQL Server
Before you start, note the logs locations.
Log file locations
Extension log
The extension log file is at:
C:\ProgramData\GuestConfig\extension_logs\Microsoft.AzureData.WindowsAgent.SqlServer\
The log file name depends on the version Azure Extension for SQL Server, for the latest version of Azure Extension for SQL Server, the log file is:
unifiedagent.log
For extension version 1.1.24724.69 and earlier, the log file is:
ExtensionLog_0.log
Deployer logs
The deployer logs are deployed at:
C:\ProgramData\GuestConfig\extension_logs\Microsoft.AzureData.WindowsAgent.SqlServer\<extension version>\deployer.log
Replace <extension version> with your extension version. For example:
C:\ProgramData\GuestConfig\extension_logs\Microsoft.AzureData.WindowsAgent.SqlServer\1.1.0.0\deployer.log
The failure to create the Arc-enabled SQL Server resource could be caused by several issues.
Extension installation failed
Go to the connected server and check the deployer log. You should see the below messages.
[YY/MM/DDDD HH:MM:SS UTC] [INFO] Status of service 'SqlServerExtension' before attempting start: Stopped
[YY/MM/DDDD HH:MM:SS UTC] [INFO] Status of service 'SqlServerExtension' after attempting start: Stopped
If you can't see it, the extension didn't install properly. Try the following steps.
Check event logs to see if anything preventing installation. Try installing SqlServerExtension.msi from the following folder
C:\Packages\Plugins\Microsoft.AzureData.WindowsAgent.SqlServer{version}. The installation UI may provide the error details.Close services app, server manager and retry one of the connection methods to install the extension, and see if that helps.
Extension installed but didn't start
Check the log files for any application errors.
Server - Azure Arc ARM resource was manually deleted
Check the extension log for the following record:
[YY/MM/DDDD HH:MM:SS PM UTC] [ERROR] [UploadServiceProvider] [ExtensionHandlerStatusQueryError] ArcSqlInstancesRequest request is null, not sending data to RP.
This means the machine is no longer recognized as a connected server. Onboard the server to Azure Arc and retry one of the connection methods to install the extension.
Server managed identity has insufficient permissions
Check the extension log for the following record:
[INFO] [UploadServiceProvider] [ExtensionHandlerArcUploadServicesNotifications] [AzureUpload] Arc post request failed with error: Forbidden message: {"ErrorDescription":{"ErrorCode":6,"Message":"The user has no access to the provided Azure resource."},"ResponseUrl":null}
Make sure the machine's managed identity has been assigned the Azure Connected SQL Server Onboarding role. See When machine already connected to Arc-enabled Server role assignment instructions.
The user didn't migrate the Arc-enabled SQL Server resource to the new resource provider
Check the extension log for the following record:
[YY/MM/DDDD HH:MM:SS PM UTC] [INFO] [UploadServiceProvider] [ExtensionHandlerArcUploadServicesNotifications] [AzureUpload] Arc for Sql Server upload response status: InternalServerError.`
Make sure to migrate the Arc-enabled SQL Server resource to Microsoft.AzureArcData.