Reply to Help with exporting tracks from rekordbox to USB

This might be a stupid question for most you but im only just starting to bare with me.

Im trying to get all my music on my rekordbox onto a USB, to do so i have highlighted the entire 'collection' and control clicked and chose 'export to...' - My usb. It then comes up saying there is not enough space when im only yrying to export 2gb onto an empty 8gb USB???