1. The scenario here we are trying to upgrade from SQL Server 2008 R2 to SQL Server 2012, so I turned off the machine (simulating power outage) while upgrade is in progress
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2. When I try to run upgrade command again, I am blocked with below rule
3. Generating discovery report by running setup.exe /Action=Runsdiscovery, we will notice majority of features still at 2008 R2 level but we have AS is at SQL Server 2012 level and it is un-configured, so we need to uninstall all features that is related to SQL Server 2012, It is important to review checklist in following article before doing uninstallation for the 2012 features
http://msdn.microsoft.com/en-us/library/ms143412(v=sql.110).aspx
4. To un-install failed 2012 features (Analysis Services) we need to run below command:
Setup.exe /action=uninstall /instanceid=MSSQLSERVER /features=<Features at 11.0.2100.60> /Q
In this case since we have only AS at SQL Server 2012 level we need to run
Setup.exe /action=uninstall /instanceid=MSSQLSERVER /features=AS /Q
5. Generating the discovery report again we now have SQL Server 2008 R2 features
6. Running the upgrade command again, it ran successfully
