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Full-Text Articles in Physical Sciences and Mathematics
Enwrich: A Compute-Processor Write Caching Scheme For Parallel File Systems, Apratim Purakayastha, Carla Schlatter Ellis, David Kotz
Enwrich: A Compute-Processor Write Caching Scheme For Parallel File Systems, Apratim Purakayastha, Carla Schlatter Ellis, David Kotz
Dartmouth Scholarship
Many parallel scientific applications need high-performance I/O. Unfortunately, end-to-end parallel-I/O performance has not been able to keep up with substantial improvements in parallel-I/O hardware because of poor parallel file-system software. Many radical changes, both at the interface level and the implementation level, have recently been proposed. One such proposed interface is \em collective I/O, which allows parallel jobs to request transfer of large contiguous objects in a single request, thereby preserving useful semantic information that would otherwise be lost if the transfer were expressed as per-processor non-contiguous requests. Kotz has proposed \em disk-directed I/O as an efficient implementation technique for …
Disk-Directed I/O For An Out-Of-Core Computation, David Kotz
Disk-Directed I/O For An Out-Of-Core Computation, David Kotz
Dartmouth Scholarship
New file systems are critical to obtain good I/O performance on large multiprocessors. Several researchers have suggested the use of \em collective\/ file-system operations, in which all processes in an application cooperate in each I/O request. Others have suggested that the traditional low-level interface (\tt read, write, seek) be augmented with various higher-level requests (e.g., \em read matrix). Collective, high-level requests permit a technique called \em disk-directed I/O\/ to significantly improve performance over traditional file systems and interfaces, at least on simple I/O benchmarks. In this paper, we present the results of experiments with an “out-of-core” LU-decomposition program. Although its …
Low-Level Interfaces For High-Level Parallel I/O, Nils Nieuwejaar, David Kotz
Low-Level Interfaces For High-Level Parallel I/O, Nils Nieuwejaar, David Kotz
Dartmouth Scholarship
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 …
Disk-Directed I/O For Mimd Multiprocessors, David Kotz
Disk-Directed I/O For Mimd Multiprocessors, David Kotz
Dartmouth Scholarship
Many scientific applications that run on today's multiprocessors are bottlenecked by their file I/O needs. Even if the multiprocessor is configured with sufficient I/O hardware, the file-system software often fails to provide the available bandwidth to the application. Although libraries and improved file-system interfaces can make a significant improvement, we believe that fundamental changes are needed in the file-server software. We propose a new technique, \em disk-directed I/O, that flips the usual relationship between server and client to allow the disks (actually, disk servers) to determine the flow of data for maximum performance. Our simulations show that tremendous performance gains …
File-System Workload On A Scientific Multiprocessor, David Kotz, Nils Nieuwejaar
File-System Workload On A Scientific Multiprocessor, David Kotz, Nils Nieuwejaar
Dartmouth Scholarship
No abstract provided.