Accession Number : ADA311424

Title :   A Structured Approach to Redundant Disk Array Implementation,

Corporate Author : CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF COMPUTER SCIENCE

Personal Author(s) : Courtright, William V., II ; Gibson, Garth ; Holland, Mark ; Zelenka, Jim

PDF Url : ADA311424

Report Date : 10 JUN 1996

Pagination or Media Count : 16

Abstract : Error recovery in redundant disk arrays is typically performed in an ad hoc fashion, requiring architecture-specific code which limits extensibility and is difficult to verify. In this paper, we describe a technique for automating the execution of redundant disk array operations, including recovery from errors, independent of array architecture. Our approach employs a graphical representation of array operations and a two-phase error-recovery scheme we refer to as roll-away error recovery. We demonstrate the validity of this approach in RAIDframe, a prototyping framework that separates architectural policy from execution mechanism. RAIDframe facilitates rapid prototyping of new RAID architectures by localizing modifications. In addition, RAIDframe-implemented architectures run the same code when configured as an event-driven simulator, a user-level application managing raw disks, and as a Digital Unix device-driver capable of mounting a file system. Evaluation shows that RAIDframe performance is equivalent to less complex array implementations and that case studies of RAID levels 0, 1, 4, 5, 6, and parity declustering achieve expected performance.

Descriptors :   *SYSTEMS ENGINEERING, *COMPUTER ARCHITECTURE, *INPUT OUTPUT PROCESSING, DATA BASES, ALGORITHMS, QUEUEING THEORY, DATA MANAGEMENT, DISTRIBUTED DATA PROCESSING, PERFORMANCE(ENGINEERING), ARRAYS, EFFICIENCY, OPERATING SYSTEMS(COMPUTERS), SYSTEMS ANALYSIS, DISKS, SUBROUTINES, COMPUTER FILES, REDUNDANCY, ERROR CORRECTION CODES, DEBUGGING(COMPUTERS), EXECUTIVE ROUTINES, CONTROL SEQUENCES, STRUCTURED PROGRAMMING, COMPUTER BENCHMARKING.

Subject Categories : Computer Systems
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE