Supplying High Availability with a Standard Network File System

This paper describes the design of a network le service that is tolerant to fail-stop failures and can be run on top of a standard network le service. The fault-tolerance is completely transparent , so the resulting le system supports the same set of heterogeneous workstations and applications as the chosen standard. To demonstrate that our design can provide the beneet of highly available les at a reasonable cost to the user, we implemented a prototype based on the Sun NFS protocol. Our approach is not limited to being used with NFS, however. And, the methodology used should apply to any network le service built along the client-server model.