GFS– Global FileSystem. AWS says a global file system (GFS) presents a single global namespace to multiple locations. This means that a client mounting the file system at any of the locations will see the same file and folder structure as clients in any other location. The benefit of using a GFS over syncing the data to multiple locations is that a GFS can be more efficient with the amount of data it transfers.

A GFS works by keeping a file’s metadata, such as its creation date, size, name and location, separate from the main payload of the file content (sometimes referred to as the essence data). The metadata is continuously synced between locations, while the payload is only transferred when required. Since the metadata for even large files takes up only a couple of kilobytes, using this system in production ends up requiring less data transfer than a full syncing system would.

The GFS abstracts these concepts away from the user. From an application’s point of view, the file system behaves the same as a local file system would. The end result is that the workflows built on top of local file systems will not need any modifications to work with a GFS.