Final Cut Pro X gives you the choice to copy media to the Final Cut Events Folder or simply refer to media files and leave them in their original location. What happens if the volume that the FInal Cut Events Folder gets full? Can you refer to more than one FInal Cut Events Folder? There's also an option to "consolidate" a project and copy media to the Final Cut Events Folder, but again, what if the project exceeds the capacity of the volume that the FInal Cut Events folder is on?

The default location for Final Cut events folder is User>Movies>Final Cut Events on your main HD but if you are importing media from an external HD it creates an Events Folder at the Root level of your device.