This chapter includes contents: To describe the physical structure of secondary storage devices and its effects on the uses of the devices, to explain the performance characteristics of mass-storage devices, to evaluate disk scheduling algorithms, to discuss operating-system services provided for mass storage including RAID. | Chapter 10: Mass-Storage Systems Operating System Concepts – 9th Edition Silberschatz, Galvin and Gagne ©2013 Chapter 10: Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk Management Swap-Space Management RAID Structure Stable-Storage Implementation Operating System Concepts – 9th Edition Silberschatz, Galvin and Gagne ©2013 Objectives To describe the physical structure of secondary storage devices and its effects on the uses of the devices To explain the performance characteristics of mass-storage devices To evaluate disk scheduling algorithms To discuss operating-system services provided for mass storage, including RAID Operating System Concepts – 9th Edition Silberschatz, Galvin and Gagne ©2013 Overview of Mass Storage Structure Magnetic disks provide bulk of secondary storage of modern computers Drives rotate at 60 to 250 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, SAS, Firewire Host controller in computer uses bus to talk to disk controller built into drive or storage array Operating System Concepts – 9th Edition Silberschatz, Galvin and Gagne ©2013 Moving-head Disk Mechanism Operating System Concepts – 9th Edition Silberschatz, Galvin and Gagne .
