SCCM 2012 R2 SQL Database Upgrade Fails : Setup cannot upgrade the ConfigMgr database. Contact your SQL administrator.

Question

Hi Friends,
We have planned to upgrade our SCCM 2012 SP1 infrastructure to SCCM 2012 R2 so we have setup test environment to test SQL database upgrade before doing same in production.
But while testing SQL database upgrade on test machine, it is getting failed with below error.
ConfigMgrSetupWizard.log
ConfigMgrSetupWizard Verbose: 1 : Scripted setup failure handling callback called. Failure: 29.
ConfigMgrSetupWizard Verbose: 1 : Received error [Setup cannot upgrade the ConfigMgr database. Contact your SQL administrator.] from native code.
ConfigMgrSetup.log
ERROR: SQL Server error: [23000][2627][Microsoft][SQL Server Native Client 11.0][SQL Server]Violation of PRIMARY KEY constraint 'ContentDistribution_PK'. Cannot insert duplicate key in object 'dbo.ContentDistribution'. The duplicate key value is (921). :
tr_ContentDistributionNotification_insert
ERROR: Failed to execute SQL Server command:  ~-- ~-- Rebuild ContentDistribution tables ~-- ~IF (EXISTS(SELECT TOP 1 1 FROM dbo.SMSData WHERE SMSBuildNumber <=  7900) AND dbo.fnIsSecondary() != 1) ~BEGIN ~    exec spRebuildContentDistribution
@TruncateTables=0 ~END
Failed to create process of SetupWpf.exe.
Can anyone please help to get this resolved.
Thanks. 

Answer 1

We found out that there were duplicate entries in the PkgStatus_G and the PkgServers_G tables in the SCCM DB.  We identified them, deleted them , and then we were able to run the /TESTDBUPGRADE command and it went through fine.  We performed
all of this on a COPY of the PROD DB and then moved the changes in PROD.  Hope this helps someone.
- Dave