I don't suppose there is a "run now" button somewhere is there?
Start > All Programs > Solarwinds Orion > Advanced Features > Database Maintenance
Also, with the addition of the new filegroups for the NetFlow data, what is the best way to migrate the database to a new server?
When restoring/attaching the database on the new server, you will have to specify all the filegroups names to be able to complete the restore/attach process. So write down their names before to move the database.
Otherwise the usual documentation should answer the rest of your questions:
Do not hesitate to ask if it does not.
But if you're looking for the NetFlow specific Database Maintenance then you'll want to run the following:
C:\Program Files\Solarwinds\Orion\NetFlowTrafficAnalysis\NetFlowDatabaseMaintenance.exe (default location)
It should be pretty self-explainatory once you run it. If not, let me know.