Tip: Discovery and other console actions not responding
If you’ve recently migrated your SCOM database to another server or a larger disk you might find that long-running tasks in the SCOM console (and in SquaredUp) do not complete. In turns out that the actions do in fact complete in the background, but the UI is never notified. This happens across a number of different actions, such as trying to run a custom task, reset a monitor or run discovery.
The reason is that SCOM relies on a SQL Server feature called the Service Broker . The Service Broker is responsible for notifying clients (like the SCOM console and the SquaredUp web console) when long-running tasks have completed. If the Service Broker is not enabled for the SCOM database then these notifications are not sent and the tasks appear to never complete.
If you detach and reattach the SCOM database you must re-enable the Service Broker. See steps 15 & 16 in the following TechNet article:
How to Move the OperationsManager Database in Operations Manager 2007 (similar steps for 2007 R2)
Note that there is also a Microsoft KB article on this issue: The Discovery Wizard may stop responding during the discovery process in Microsoft System Center Operations Manager, but the TechNet articles above contain more reliable steps.