Document Type

Conference Paper

Publication Date

4-1995

Publication Title

Proceedings of the IPPS '95 Workshop on Input/Output in Parallel and Distributed Systems (IOPADS)

Department

Department of Computer Science

Abstract

As the I/O needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. By tracing all the activity of a parallel file system in a production, scientific computing environment, we show that many applications exhibit highly regular, but non-consecutive I/O access patterns. Since the conventional interface does not provide an efficient method of describing these patterns, we present three extensions to the interface that support \em strided, \em nested-strided, and \em nested-batched I/O requests. We show how these extensions can be used to express common access patterns.

As the I/O needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. By tracing all the activity of a parallel file system in a production, scientific computing environment, we show that many applications exhibit highly regular, but non-consecutive I/O access patterns. Since the conventional interface does not provide an efficient method of describing these patterns, we present three extensions to the interface that support \em strided, \em nested-strided, and \em nested-batched I/O requests. We show how these extensions can be used to express common access patterns.

Comments

A result of the CHARISMA project.

Listed in the Dartmouth College Computer Science Technical Report Series as PCS-TR95-253 (supersedes PCS-TR94-230).

Original Citation

Nils Nieuwejaar and David Kotz. Low-level Interfaces for High-level Parallel I/O. InProceedings of the IPPS '95 Workshop on Input/Output in Parallel and Distributed Systems (IOPADS), April 1995.

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