SCOM 2012 OleDB Module 0x80004005 errors after SQL database move

After migrating our SCOM 2012 R2 DB and Data Warehouse DB to a new SQL server we were receiving SCOM alerts that there was a problem with the OleDB module.


The Problem

The initial alert indicated that there was a login problem. This prompted us to check, re-check and triple-check all the SQL logins and permissions between the old and new SQL servers.

Alert description: OleDb Module encountered a failure 0x80004005 during execution and will post it as output data item. Unspecified error: Cannot open database "OperationsManager2012" requested by the login. The login failed.
Workflow name: Microsoft.SystemCenter.SqlBrokerAvailabilityMonitorForPool

After not having much luck we eventually decommissioned the old SQL server. Once the old SQL server was turned off, the alert changed from a login failed to a "SQL server does not exist". This error got us thinking, maybe its not a permission problem but some parts of SCOM may have been still pointing at the old SQL server.

Alert description: OleDb Module encountered a failure 0x80004005 during execution and will post it as output data item. Unspecified error: [DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied.
Workflow name: Microsoft.SystemCenter.SqlBrokerAvailabilityMonitorForPool

The Solution 

A search of the registry found a few keys that were undocumented in the SQL migration document I was reading. These keys are:

HKLM\SOFTWARE\Microsoft\Microsoft Operations Manager\3.0\Setup\DatabaseServerName
HKLM\SOFTWARE\Microsoft\Microsoft Operations Manager\3.0\Setup\DataWarehouseDBServerName
HKLM\Software\Microsoft\System Center\SetupBackup\Blue\Database\DatabaseServerName

After changing these keys and restarting the SCOM server all was well!