Step 1: Install & Configure SSRS 2012

The installation and configuration of the new 2012 instance.

Step 2: Backup Encryption Keys

Encryption keys are used to encrypt (no surprise) the contents of your Report Server databases. This is required for various reasons, but mostly due to the fact that credentials of data sources can be stored within Reporting Services. If it wasn’t encrypted, anybody with access to the ReportServer database would be able to see all your data source account and password information.

If you are going to restore/move the SSRS databases (ReportServer and ReportServerTempDB) on/to the 2012 instance, you will need the encryption keys from the old environment. A very important fact to remember is that you will lose all your connection and subscription information should you delete the encryption key. The Reporting Services Configuration Manager can be used to back up encryption keys.

Step 3: Restore ReportServer and ReportServerTempDB databases

If your SSRS databases are small enough, you could actually opt to detach (from 2005 instance), copy (to new 2012 server) and attach (to 2012 instance) them rather than backup and restore. An important point to here is to stop the SSRS service on the new instance before attaching or restoring the content databases.

After the content databases are restored/attached, you simply need to change the compatibility level (of both) to 110 for SQL Server 2012, and start the service. The upgrade happens at this point…and yes, it is as simple as that!!!

Step 4: Select reporting service database. The Reporting Services Configuration Manager

change database, select the new restored reporting database.

Step 5: Restore Encryption Keys

You should receive an error if you try to access the Report Manager on the new 2012 instance at this point. The reason for that is because the encryption keys (automatically generated when SSRS 2012 was installed) is no longer able to decrypt the information in the newly restored/attached content databases.

To resolve the issue you simply have to restore the encryption keys that you backed up from the old SSRS 2005 instance, and restart the services. Use the Reporting Services Configuration Manager for this task.

Step 6: Update Data Sources

Don’t forget to verify all your data sources. You may have to update some of these to point to the right database server.

Step 7: Check: Scale-out deployment in reporting services configuration

ReportServer/Keys/ delete the server

From my SQL Server DBA handbook.