VOFS: A Secure Churn-Tolerant Grid File System

Abstract

A Grid computing environment allows forming Virtual Organizations (VOs) to aggregate and share resources. We present a VO File System (VOFS) which is a secure VO-aware distributed file system that allows VO members to share files within a VO. VOFS supports access and location transparency by maintaining a common file namespace, which is decentralized to avoid a single point of failure in order to improve robustness of the file system. VOFS includes a P2P system of file servers, a VO membership service and a policy and role based security mechanism that protects the VO files from unauthorized access. VOFS can be mounted to a local file system in order to access files using a standard POSIX file API. VOFS can operate in a dynamic Grid environment (e.g. desktop Grids) since it is able to tolerate unplanned resource arrival and departure (churn) while maintaining a single uniform namespace. It supports transparent disconnected operations that allow the user to work on cached files while being disconnected. Furthermore, VOFS is a user level technique, and the current WebDAV-based VOFS prototype can operate under any operating system that has WebDAV mount support.