A Storage Management System for a Reliable Distributed Operating System
Abstract
Decentralization of computing systems has several attractions: performance enhancements due to increased parallelism; resource sharing; and the increased reliability and availability of data due to redundant copies of the data. Providing these characteristics in a decentralized system requires proper organization of the system. With respect to increasing the reliability of a system, one model which has proven successful is the object/action model, where tasks performed by the system are organized as sequences of atomic operations. The system can determine which operations have been performed completely and so maintain the system in a consistent state. This dissertation describes the design and a prototype implementation of a storage management system for an object-oriented, action-based decentralized kernel. The storage manager is responsible for providing reliable secondary storage structures. First, the dissertation shows how the object model is supported at the lowest levels in the kernel by the storage manager. It also describes how storage managemet facilities are integrated into the virtual memory management provided by the kernel to support the mapping of objects into virtual memory. All input and output to secondary storage is done via virtual memory management. This disserttion discusses the role of the storage management system in locating objects, and a technique intended to short circuit searches whenever possible by avoiding unnecessary secondary storage queries at each site. It also presents a series of algorithms which support two-phase commit of atomic actions and then argues that these algorithms do indeed provide consistent recovery of object data. These algorightms make use of virtual memory management information to provide recovery, and relieve the action management system of the maintenance of the stable storage.
Address
School of Information and Computer Science
Georgia Institute of Technology
Atlanta, GA 30332-0280
Pages
SUNW177421-SUNW177567
Publisher
Georgia Institute of Technology
School
Georgia Institute of Technology
Affiliation
Georgia Institute of Technology
Publication Date
1986-10-23
Location
A hard-copy of this is in the Papers Cabinet
Subject
Storage Management System