Towards Higher Disk Head Utilization: Extracting Free" Bandwidth From Busy Disk Drives"

Lumb, Christopher R.; Schindler, Jiří; Ganger, Gregory R.; Riedel, Erik; Nagle, David F.

doi:10.21236/ada382318

Cited by 48 publications

(53 citation statements)

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“…Since I/O requests usually fall into several patterns in parallel file systems, it is possible to reorganize the data layout to reduce the number of disk seeks [19][20] [21]. These data reorganization techniques improve the overall I/O performance due to a prior knowledge of application I/O behaviors.…”

Section: B Layout Optimizationmentioning

confidence: 99%

A Server-Level Adaptive Data Layout Strategy for Parallel File Systems

Song

Jin

et al. 2012

2012 IEEE 26th International Parallel and Distributed Processing Symposium Workshops &Amp; PhD Forum

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Abstract-Parallel file systems are widely used for providing a high degree of I/O parallelism to mask the gap between I/O and memory speed. However, peak I/O performance is rarely attained due to complex data access patterns of applications. Based on the observation that the I/O performance of small requests is often limited by the request service rate, and the performance of large requests is limited by I/O bandwidth, we take into consideration both factors and propose a server-level adaptive data layout strategy. The proposed strategy adopts different stripe sizes for different file servers according to the data access characteristics on each individual server. We let the file servers that can fully utilize bandwidth hold more data, and the file servers that are limited with request service rate hold less data. As a result, heavy-load servers can offload some data accesses to light-load servers for potential improvement of I/O performance. We present a method to measure access cost for each data block and then utilize an equal-depth histogram approach to distributed data blocks across multiple servers adaptively, so as to balance data accesses on all file servers. Analytical and experimental results demonstrate that the proposed server-level adaptive layout strategy can improve I/O performance by as much as 80.3% and is more appropriate for applications with complex data access patterns.Keywords-Server-level adaptive data layout, variable stripe size, equal-depth histogram, data layout optimization, parallel file system

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Section: B Layout Optimizationmentioning

confidence: 99%

A Server-Level Adaptive Data Layout Strategy for Parallel File Systems

Song

Jin

et al. 2012

2012 IEEE 26th International Parallel and Distributed Processing Symposium Workshops &Amp; PhD Forum

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“…Both impacts result in shorter seek time in terms of equation (3). Though the seek time has been decreased significantly due to the increasing BPI, the Lumb et al[2000] investigated the impact of seek time, rotational latency and data transfer time that add up to 100% of the disk head utilization for five modern disk drives which were sold on the market from 1996 to 1999. The investigation indicated that the faster seek of the Cheetah 18LP (average seek time 5.2ms), relative to the Cheetah 9LP and Cheetah 4LP which have average seek time of 5.4ms and 7.7ms respectively, resulted in lower seek components.…”

Section: Seek Timementioning

confidence: 99%

What is the future of disk drives, death or rebirth?

Deng

2011

ACM Comput. Surv.

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________________________________________________________________________Disk drives have experienced dramatic development to meet the performance requirements, since the IBM 1301 disk drive was announced in 1961. However, the performance gap between memory and disk drives has widened to 6 orders of magnitude and continues to widen by about 50% per year. Furthermore, energy efficiency has become one of the most important challenges in designing disk drive storage systems. The architectural design of disk drives has reached a turning point which should allow their performance to advance further, while still maintaining high reliability and energy efficiency. This paper explains how disk drives have evolved over five decades to meet challenging customer demands. First of all, it briefly introduces the development of disk drives, and deconstructs disk performance and power consumption. Secondly, it describes the design constraints and challenges that traditional disk drives are facing. Thirdly, it presents some innovative disk drive architectures discussed in the community. Fourthly, it introduces some new storage media types and the impacts they have on the architecture of the traditional disk drives. Finally, it discusses two of the important evolutions of the disk drives: hybrid disk and solid state disk. The paper highlights the challenges and opportunities facing these storage devices, and explores how we can expect them to affect the storage systems.

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“…In addition, when supervisors decide to move data from one worker to another, it should be a direct transfer (via a worker-to-worker COPY request) rather than passing through an intermediary. Further, maintenance functions such as these should happen with minimal effect on real user workloads, requiring careful scheduling of network usage [5,33] and disk activity [20,35].…”

Section: Workersmentioning

confidence: 99%

“…Disk bandwidth for maintenance functions will be provided by freeblock scheduling [35], which we have implemented [34] and refined into a working system. For most access patterns, it gives background disk maintenance activities 15-40% of the disk head's time with near-zero impact on foreground activity (i.e., real user requests).…”

Section: Building Blocksmentioning

confidence: 99%