If you have data in several folders on your harddrives that actually should be seen as one folder, you may create a virtual file system by adding more resources to the same folder. This will be seen as one big folder for the users connecting to your server.
Examples:You have some pictures stored in one location and another set of pictures stored in another location, then you may add those two locations as “Resources” to a particular “Folder” and then it will seem as all files and subdirectories are in the same folder (for users connecting to your server).Another useful way of using this feature is for instance by adding an upload resource to some folders, that way users may upload files to, what they see, some folders. However, the files are actually sent to a particular upload folder on the location you specified. When specifying upload folders, it may be usefull to add more than one resource since then the files being uploaded to that folder will physically end up on the resource with the most available space (it will seem as you have a huge upload folder).