Ch12 - perating System Concepts with Java – 7 th Edition Silberschatz Galvin and Gagne ©2007 Chapter 12 Mass-Storage Systems 12.2 Silberschatz

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: perating System Concepts with Java – 7 th Edition, Nov 15, 2006 Silberschatz, Galvin and Gagne ©2007 Chapter 12: Mass-Storage Systems 12.2 Silberschatz, Galvin and Gagne ©2007 Operating System Concepts with Java – 7 th Edition, Nov 15, 2006 Chapter 12: Mass-Storage Systems ¡ Overview of Mass Storage Structure ¡ Disk Structure ¡ Disk Attachment ¡ Disk Scheduling ¡ Disk Management ¡ Swap-Space Management ¡ RAID Structure ¡ Disk Attachment ¡ Stable-Storage Implementation ¡ Tertiary Storage Devices ¡ Operating System Issues ¡ Performance Issues 12.3 Silberschatz, Galvin and Gagne ©2007 Operating System Concepts with Java – 7 th Edition, Nov 15, 2006 Objectives ¡ Describe the physical structure of secondary and tertiary storage devices and the resulting effects on the uses of the devices ¡ Explain the performance characteristics of mass- storage devices ¡ Discuss operating-system services provided for mass storage, including RAID and HSM 12.4 Silberschatz, Galvin and Gagne ©2007 Operating System Concepts with Java – 7 th Edition, Nov 15, 2006 Overview of Mass Storage Structure ¡ Magnetic disks provide bulk of secondary storage of modern computers ¢ Drives rotate at 60 to 200 times per second ¢ Transfer rate is rate at which data flow between drive and computer ¢ Positioning time ( random-access time ) is time to move disk arm to desired cylinder ( seek time ) and time for desired sector to rotate under the disk head ( rotational latency ) ¢ Head crash results from disk head making contact with the disk surface ¡ That’s bad ¡ Disks can be removable ¡ Drive attached to computer via I/O bus ¢ Busses vary, including EIDE, ATA, SATA, USB, Fibre Channel, SCSI ¢ Host controller in computer uses bus to talk to disk controller built into drive or storage array 12.5 Silberschatz, Galvin and Gagne ©2007 Operating System Concepts with Java – 7 th Edition, Nov 15, 2006 Moving-head Disk Mechanism 12.6 Silberschatz, Galvin and Gagne ©2007 Operating System Concepts with Java – 7 th Edition, Nov 15, 2006 Overview of Mass Storage Structure (Cont.) ¡ Magnetic tape ¢ Was early secondary-storage medium ¢ Relatively permanent and holds large quantities of data ¢ Access time slow ¢ Random access ~1000 times slower than disk ¢ Mainly used for backup, storage of infrequently-used data, transfer medium between systems ¢ Kept in spool and wound or rewound past read-write head ¢ Once data under head, transfer rates comparable to disk ¢ 20-200GB typical storage ¢ Common technologies are 4mm, 8mm, 19mm, LTO-2 and SDLT 12.7 Silberschatz, Galvin and Gagne ©2007 Operating System Concepts with Java – 7 th Edition, Nov 15, 2006 Disk Structure ¡ Disk drives are addressed as large 1-dimensional arrays of logical blocks , where the logical block is the smallest unit of transfer....
View Full Document

This note was uploaded on 09/08/2010 for the course CS 149 at San Jose State University .

Page1 / 49

Ch12 - perating System Concepts with Java – 7 th Edition Silberschatz Galvin and Gagne ©2007 Chapter 12 Mass-Storage Systems 12.2 Silberschatz

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online