A transparent service for synchronized replication across loosely-connected file systems

Abstract

n-DFS/Parrot is a service that provides synchronized file replication across two loosely-connected file systems. It propagates the modification of replicated files and directories from either file system to the other. Parrot guarantees sequential write sharing over a local- or wide-area network: file access under Parrot has exactly the same semantics as if all of the processes on both hosts were executing on a single time-sharing system and sharing a single copy of each file. Parrot implements a read-one write-all replication scheme as a shared library that runs within an application's address space. It preserves the operating system interface between applications and the file system; it requires no modification in the kernel or the applications.<>