Multi-resident AFS: an adventure in mass storage

The Pittsburgh Supercomputing Center has been working to integrate distributed file system technology with hierarchical mass storage. We produced a system utilizing the Andrew File System that can be interfaced to many mass storage systems. We retained the semantics of AFS and compatibility with standard clients and servers. The architecture has a logical separation between the facility that provides the user interface and access semantics and the management of the storage systems that contain user data. Support for file level replication is provided for high availability to data in a fashion that is transparent to users. This system is called Multi-Resident AFS.