*-Box: Towards Reliability and Consistency in Dropbox-like File Synchronization Services

Cloud-based file synchronization services, such as Dropbox, have never been more popular. They provide excellent reliability and durability in their server-side storage, and can provide a consistent view of their synchronized files across multiple clients. However, the loose coupling of these services and the local file system may, in some cases, turn these benefits into drawbacks. In this paper, we show that these services can silently propagate both local data corruption and the results of inconsistent crash recovery, and cannot guarantee that the data they store reflects the actual state of the disk. We propose techniques to prevent and recover from these problems by reducing the separation between local file systems and synchronization clients, providing clients with deeper knowledge of file system activity and allowing the file system to take advantage of the correct data stored remotely.