I have a SQL Server 2005 instance on my PROD server. I have been given a task to migrate databases from that instance to a different box (SQL Server 2008 R2 on Windows 2008 R2). The current instance has a maintenance plan set up, which backs up 8 different databases every night to a single .bak file.
How do I take that bak file and restore it onto the new SQL Server 2008 R2 instance? I have tried using SQL Server 2008 R2 SSMS, and set the restore from option to device and point it to that .bak file, but what should I target restore to since I have multiple databases to be restored in the new instance?
What is the best approach to migrate all databases in single shot to the new instance without doing one at a time?