E-Locus - Institutional Repository of the University of Crete - Μειώνοντας την Ευαισθησία των Δίσκων του Υποσυστήματος Εισόδου/Εξόδου για Μεγάλο Αριθμό Διαδοχικών Ροών Δεδομένων

Home Μειώνοντας την Ευαισθησία των Δίσκων του Υποσυστήματος Εισόδου/Εξόδου για Μεγάλο Αριθμό Διαδοχικών Ροών Δεδομένων

Results - Details

[Add to Basket]

Identifier

uch.csd.msc//2006panagiotakis

Title

Μειώνοντας την Ευαισθησία των Δίσκων του Υποσυστήματος Εισόδου/Εξόδου για Μεγάλο Αριθμό Διαδοχικών Ροών Δεδομένων

Alternative Title

Reducing Disk I/O Performance Sensitivity for Large Numbers of Sequential Streams

Creator

Panagiotakis, Georgios

Abstract

Over the last few years I/O subsystem performance issues have attracted significant attention due to the increasing needs for storing and retrieving information. Cost-efective, large-scale storage systems can enable novel online content delivery services. In particular, rich media content is becoming increasingly popular due its importance for entertainment, education, and other application domains. However, retrieving sequential rich media content from modern commodity disks is a challenging task. As disk capacity increases, there is a need to increase the number of streams that are allocated to each disk. However, when multiple streams are accessing a single disk, throughput is dramatically reduced because of disk head seek overhead, resulting in higher requirements for disk numbers. Thus, there is a trade between how many streams should be allowed to access a disk and the total throughput that can be achieved. In this work we first examine this tradeof using simulation. We use Disksim, a detailed architectural simulator, to examine several aspects of an I/O subsystem and we show the effect of various disk parameters on system performance under multiple sequential streams. Then, we propose a solution that adjusts I/O request streams, based on host and I/O subsystem parameters. We implement our approach in a real system and perform experiments with a small and a large disk configuration. Our approach improves disk throughput up to a factor of 8 with a workload of 100 sequential streams, without requiring large amounts of memory on the storage node. Moreover, it is able to adjust (statically) to different storage node configurations, essentially making the I/O subsystem insensitive to the number of I/O streams used.

Issue date

2006-09-01

Date available

2006-11-23

Collection

School/Department--School of Sciences and Engineering--Department of Computer Science--Post-graduate theses

Type of Work--Post-graduate theses

Views

411

Digital Documents
	Download document View document Views : 2