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Storage management activities, such as reporting, file placement, migration and archiving, require the ability to discover files that belong to an application workflow by relying only on information from the file server. Some classes of application workflows, such as rendering an animated sequence from its graphics models or building an application from its source files, often exhibit a high degree of repeatability. We describe a system called Autograph that exploits this repeatability to discover files that belong to an application workflow. Our approach examines traces of file accesses, finds repeated and correlated accesses, and infers which files likely belong to the same workflow. Our solution targets server workflows and uses file server traces, which contain less process and file information than the local machine traces used in prior work. We show that Autograph successfully extracts workflow file signatures, even if the workflows are concurrent or share files.

Knowledge of the file size distribution is needed to optimize file system design. In particular, if all the files are small, the disk block size should be small, too, to avoid wasting too large a fraction of the disk. On the other hand, if files are generally large, choosing a large block size is good since it leads to more efficient transfers. Only by knowing the file size distribution can reasonable choices be made. In 1984, we published the file size distribution for a university computer science department. We have now made the same measurements 20 years later to see how file sizes have changed. In short, the median file size has more than doubled (from 1080 bytes to 2475 bytes), but large files still dominate the storage requirements.

Pangaea is a wide-area file system that supports data sharing among a community of widely distributed users. It is built on a symmetrically decentralized infrastructure that consists of commodity computers provided by the end users. Computers act autonomously to serve data to their local users. When possible, they exchange data with nearby peers to improve the system's overall performance, availability, and network economy. This approach is realized by aggressively creating a replica of a file whenever and wherever it is accessed.This paper presents the design, implementation, and evaluation of the Pangaea file system. Pangaea offers efficient, randomized algorithms to manage highly dynamic and potentially large groups of file replicas. It applies optimistic consistency semantics to replica contents, but it also offers stronger guarantees when required by the users. The evaluation demonstrates that Pangaea outperforms existing distributed file systems in large heterogeneous environments, typical of the Internet and of large corporate intranets.

There exist a number of file systems with different solutions to the problems of data access, concurrency control [1], serializing transactions [5], deadlock control and recoverability. There are pros and cons to every solution, and not all solutions are independent of each other. Also, depending on the applications, a file system can be designed in several different ways.

This paper compares two working network-based file servers, the Xerox Distributed File System (XDFS) implemented at the Xerox Palo Alto Research Center, and the Cambridge File Server (CFS) implemented at the Cambridge University Computer Laboratory. Both servers support concurrent random access to files using atomic transactions, both are connected to local area networks, and both have been in service long enough to enable us to draw lessons from them for future file servers. We compare the servers in terms of design goals, implementation issues, performance, and their relative successes and failures, and discuss what we would do differently next time.