I'm reading "Seven Databases in Seven Weeks". Could you please explain me the text below:
One downside of a distributed system can be the lack of a single coherent filesystem. Say you operate a website where users can upload images of themselves. If you run several web servers on several different nodes, you must manually replicate the uploaded image to each web server’s disk or create some alternative central system. Mongo handles this scenario by its own distributed filesystem called GridFS.
Why do you need replicate manually uploaded images? Does they mean some of the servers will have linux and some of them Windows?
Do all replicated data storages tend to implement own filesystem?