A Distributed filesystem framework for transparent accessing heterogeneous storage services

This paper introduces an extensible distributed file system framework, YaFS, using heterogeneous online storage services as its back-ends. It provides a configurable solution for simplifying the usage of multiple storage resources and accessing data ubiquitously and safely. YaFS is POSIX compliant, so that it could support most of the existing applications seamlessly. An offline mode is used to cope with the challenged unreliable network environment. We implement a storage abstraction layer and a plug-in mechanism for uniformly accessing different storage services transparently, and it makes the system expanded easily. YaFS could effectively support for storing large object to size limited services and achieving high aggregate bandwidth by striping data on multiple servers with bandwidth-saving method. The evaluation on a prototype implementation with email services as its storage back-end shows that the performance and usability of the framework is viable.