There is a difference how migration upgrade process used to impact RS till TFS 2010 RC and now with TFS 2010 RTM. After the TFS 2005\2008 to TFS 2010 RC\Beta2 upgrade, RS part is pretty much untouched, i.e., any old reports are still going to be based on old data sources & old warehouse dbs in the relational & analytical stores.
So if I had a TFS 2008 report called “Remaining Work” for my TFS 2008 team project “Agile001”, then before the upgrade happens the report will be based on 2 data sources called TfsOlapReportsDS & TfsReportsDS. These data sources would be pulling data from databases hosted in the SSDE & SSAS stores. The name of the db in each SQL component is TfsWarehouse. Till TFS 2010 RC the upgrade experience(in-place or migration upgrade) leaves the existing reports un-touched, i.e., post TFS 2008\2005 to TFS 2010 RC upgrade, existing reports are still based on the same data sources & the same dbs. The upgrade wizard however creates two new data sources called Tfs2010OlapReportDs & Tfs2010ReportDS & new reports for new Team Project are created in /TfsReports/CollectionName on the Reports Manager site.
Now the big change with TFS 2010 RTM, the old TFS 2005\TFS 2008 reports will migrate successfully to TFS 2010 RTM.
So suppose you have a TFS 2008 server that needs to be upgraded to TFS 2010 RTM using migration upgrade onto a new box.
Before starting the upgrade wizard one has to ensure that Reports are configured on the TFS 2010 RTM server with the backups of the RS dbs from the other server in the context of a migration upgrade. This includes connecting to the RS dbs in RS Config Mgr->restoring encryption key->breaking scale out deployment using rskeymgmt -> updating the TfsOlapReportsDS & TfsReportsDS.
If we do an in-place upgrade to TFS 2010 RTM, the RS on the box should not need any re-configuration.
With RS(& optionally WSS) configured on the box which is the upgrade candidate, we can use the TFS 2010 RTM upgrade wizard to upgrade TFS 2008 to TFS 2010 RTM. The upgrade process will automatically create the required folder structure under the/TfsReports/CollectionName folder in RS manager & will created folders under it for each of the TFS 2008 Team Project & will upload reports to them.(Neat!!) These reports are correctly bound to the new TFS 2010 RTM data sources.
However you may have to rebuild the Tfs Cube using TfsMgmt.exe & process the relations & analytical dbs using the methods provided by the http://localhost:8080/tfs/TeamFoundation/Administration/v3.0/WarehouseControlService.asmx web service if required.
All old reports will work now.
One last thing if you have created some custom reports in TFS 2005\TFS 2008, you will need to manually fix some of the “potential” issues if required and happening using the guidance offered in: