What This Document Is
This material represents Part Two of Week Eleven for a graduate-level Special Topics course (CSCI 599) at the University of Southern California. It delves into the intricacies of distributed file systems, specifically focusing on systems designed for disconnected operation. The core case study revolves around the Coda file system, exploring its architecture and design choices. It’s a technical deep dive intended for students with a solid foundation in operating systems and distributed computing concepts.
Why This Document Matters
This resource is invaluable for students seeking a comprehensive understanding of how file systems can maintain functionality and data integrity even when network connectivity is intermittent or unavailable. It’s particularly relevant for those interested in mobile computing, edge computing, or any application where reliable access to data in disconnected environments is crucial. It will be most useful when studying distributed systems design, cache coherence protocols, and the trade-offs involved in optimizing for availability versus consistency. Students preparing for advanced research in these areas will find this a strong foundation.
Common Limitations or Challenges
This material presents a detailed exploration of a specific file system (Coda) and its design principles. It does *not* offer a broad survey of all distributed file systems, nor does it provide a practical, hands-on implementation guide. The focus is on the theoretical underpinnings and design rationale, rather than step-by-step instructions or code examples. It assumes a pre-existing understanding of core operating system and networking concepts.
What This Document Provides
* An overview of the Coda file system’s architecture and key components (Volumes, VSGs, AVSGs, Callbacks).
* A detailed examination of the design rationale behind Coda’s approach to disconnected operation.
* A comparative analysis of different replication control strategies (optimistic vs. pessimistic).
* An exploration of the Venus cache manager’s internal states and operational phases (Hoarding, Emulation, Reintegration).
* Discussion of the challenges associated with maintaining cache coherence during disconnection and reconnection.
* Insights into the trade-offs between performance, scalability, and data consistency in distributed file systems.
