So following the migration docs and got to the point of actually migrating the exchange accounts and user data. Using the migration wizard I get the following error: "A drive cannot be found. Either there are no NTFS drives available, or the available drives do not have enough capacity."
Now there is about 400GB of total data including OS on the old server, the new server has 900GB of free space. Any ideas? I can manually move the exchange accounts and data but why isn't the wizard working?