CSE325 Principles of Operating Systems. Mass-Storage Systems. David P. Duggan. April 19, 2011

Size: px
Start display at page:

Download "CSE325 Principles of Operating Systems. Mass-Storage Systems. David P. Duggan. April 19, 2011"

Transcription

1 CSE325 Principles of Operating Systems Mass-Storage Systems David P. Duggan April 19, 2011

2 Outline Storage Devices Disk Scheduling FCFS SSTF SCAN, C-SCAN LOOK, C-LOOK Redundant Arrays of Inexpensive Disks RAID 0-6 4/21/11 CSE325 - Storage 2

3 Devices: Magnetic Disks Purpose Long-term, nonvolatile storage Large, inexpensive, slow level in the storage hierarchy Characteristics Seek Time positional latency rotational latency Rotational rate 60 to 200 times per second Capacity Terabytes Quadruples every 3 years 3

4 Moving-head Disk Mechanism 4/21/11 4

5 Disk Structure Disk drives are addressed as large 1-dimensional arrays of logical blocks, where the logical block is the smallest unit of transfer. The 1-dimensional array of logical blocks is mapped into the sectors of the disk sequentially. Sector 0 is the first sector of the first track on the outermost cylinder. Mapping proceeds in order through that track, then the rest of the tracks in that cylinder, and then through the rest of the cylinders from outermost to innermost. 4/21/11 CSE325 - Storage 5

6 Magnetic Tapes Much slower than magnetic disk in positioning Comparable speeds when reading and writing Capacity from 20GB to 200GB Long term storage 4/21/11 CSE325 - Storage 6

7 Network-Attached Storage Network-attached storage (NAS) is storage made available over a network rather than over a local connection (such as a bus) NFS and CIFS are common protocols Implemented via remote procedure calls (RPCs) between host and storage iscsi protocol uses IP network to carry the SCSI protocol Performance problems? 4/21/11 7

8 Storage Area Network Common in large storage environments (and becoming more common) Multiple hosts attached to multiple storage arrays - flexible 4/21/11 CSE325 - Storage 8

9 Disk Scheduling The operating system is responsible for using hardware efficiently for the disk drives, this means having a fast access time and disk bandwidth. Access time has two major components Seek time is the time for the disk to move the heads to the cylinder containing the desired sector. Rotational latency is the additional time waiting for the disk to rotate the desired sector to the disk head. Minimize seek time Seek time seek distance Disk bandwidth is the total number of bytes transferred, divided by the total time between the first request for service and the completion of the last transfer. 4/21/11 CSE325 - Storage 9

10 Disk Scheduling (Cont.) Several algorithms exist to schedule the servicing of disk I/O requests. We illustrate them with a request queue (0-199). 98, 183, 37, 122, 14, 124, 65, 67 Head pointer 53 4/21/11 CSE325 - Storage 10

11 FCFS Illustration shows total head movement of 640 cylinders." Can you develop a better disk scheduler? 4/21/11 11

12 SSTF Selects the request with the minimum seek time from the current head position. SSTF scheduling is a form of SJF scheduling; may cause starvation of some requests. Can you further improve the performance? 4/21/11 12

13 SCAN The disk arm starts at one end of the disk, and moves toward the other end, servicing requests until it gets to the other end of the disk, where the head movement is reversed and servicing continues. Sometimes called the elevator algorithm. 4/21/11 CSE325 - Storage 13

14 SCAN (Cont.) Head movement of 236 cylinders. 4/21/11 CSE325 - Storage 14

15 C-SCAN Provides a more uniform wait time than SCAN. The head moves from one end of the disk to the other, servicing requests as it goes. When it reaches the other end, however, it immediately returns to the beginning of the disk, without servicing any requests on the return trip. Treats the cylinders as a circular list that wraps around from the last cylinder to the first one. 4/21/11 CSE325 - Storage 15

16 C-SCAN (Cont.) Is there a problem here? 4/21/11 CSE325 - Storage 16

17 C-LOOK Version of C-SCAN Arm only goes as far as the last request in each direction, then reverses direction immediately, without first going all the way to the end of the disk. 4/21/11 CSE325 - Storage 17

18 C-LOOK (Cont.) 4/21/11 CSE325 - Storage 18

19 Selecting a Disk-Scheduling Algorithm SSTF is common and has a natural appeal SCAN and C-SCAN perform better for systems that place a heavy load on the disk. Performance depends on the number and types of requests. Requests for disk service can be influenced by the fileallocation method. The disk-scheduling algorithm should be written as a separate module of the operating system, allowing it to be replaced with a different algorithm if necessary. Either SSTF or C-LOOK is a reasonable choice for the default algorithm. 4/21/11 CSE325 - Storage 19

20 Disk Management Disk initialization Booting from disk Bad blocks 4/21/11 CSE325 - Storage 20

21 Disk Initialization Formatting Low-level or physical Usually done at factory now Sectors contain ECC for fixing errors Partitioning Break disk into groups of cylinders (logical disks) Formatting Creating filesystem 4/21/11 CSE325 - Storage 21

22 Booting from Disk Boot block Bootstrap code finds and loads OS kernel Uses boot partition Boot sequence/process Read Master-Boot-Record Located in first sector on bootable disk Directs load to come from first sector of boot partition 4/21/11 CSE325 - Storage 22

23 Bad Blocks Disks can fail! Poor manufacturing Tight tolerances Plain old use Sector sparing Spare sectors used when OS or disk finds bad blocks Could invalidate efficiencies OS has made Sector slipping Slide sectors down to first free spare sector 4/21/11 CSE325 - Storage 23

24 Swap Space Management Use Overestimate rather than underestimate Separate disks spreads out I/O load Location In filesystem Separate partition Decisions When to use swap space? 4/21/11 CSE325 - Storage 24

25 Redundant Arrays of (Inexpensive) Disks Files are "striped" across multiple disks Redundancy yields high data availability Availability: service still provided to user, even if some components failed Disks will still fail Contents reconstructed from data redundantly stored in the array Capacity penalty to store redundant info Bandwidth penalty to update redundant info 4/21/11 CSE325 - Storage 25

26 RAID Levels 4/21/11 CSE325 - Storage 26

27 Redundant Arrays of Inexpensive Disks RAID 1: Disk Mirroring/Shadowing recovery! group! Each disk is fully duplicated onto its mirror Very high availability can be achieved Bandwidth sacrifice on write: Logical write = two physical writes Reads may be optimized (How?) Most expensive solution: 100% capacity overhead RAID 2: Disks are synchronized and striped in single bytes/words; Hamming code parity. 4/21/11 27

28 RAID 3: Bit-Interleaved Parity Organization Parity Disk ! ! !.. logical record! P! Byte-level striping P contains sum of other disks per stripe mod 2 ( parity ) If disk fails, subtract P from sum of other disks to find missing information Bit Interleaved Parity 28

29 RAID 3 Sum computed across recovery group to protect against hard disk failures, stored in P disk Logically, a single high capacity, high transfer rate disk: good for large transfers 33% capacity cost for parity if 3 data disks and 1 parity disk Wider arrays reduce capacity costs, but decreases availability 4/21/11 CSE325 - Storage 29

30 Inspiration for RAID 4 Allows independent reads to different disks simultaneously Block-level parity with parity on a separate disk from all data blocks Can add new disks by initializing data to 0 4/21/11 CSE325 - Storage 30

31 RAID 4 Block-Interleaved Parity Organization High I/O Rate Parity Insides of 5 disks! D0! D1! D2! D3! P! D4! D5! D6! D7! P! Increasing" Logical" Disk " Address" D8! D9! P! D10! D11! Example:! small read D0 & D5, large write D12-D15! Block Interleaved Parity D12! P! D13! D14! D15! D16! D17! D18! D19! P! D20! D21! D22! D23! P! Disk Columns! Stripe! 31

32 Inspiration for RAID 5 RAID 4 works well for large reads Small writes (write to one disk): Option 1: read other data disks, create new sum and write to Parity Disk Option 2: since P has old sum, compare old data to new data, add the difference to P Small writes are limited by Parity Disk: Write to D0, D5 both also write to P disk D0! D1! D2! D3! P! D4! D5! D6! D7! P! 4/21/11 32

33 RAID 5: Block-Interleaved Distributed Parity High I/O Rate Interleaved Parity Independent writes! possible because of! interleaved parity! Example: write to D0, D5 uses disks 0, 1, 3, 4! D0! D1! D2! D3! P! D4! D5! D6! P! D7! D8! D9! P! D10! D11! D12! P! D13! D14! D15! P! D16! D17! D18! D19! D20! D21! D22! D23! P! Disk Columns! Increasing! Logical! Disk! Addresses! 33

34 Problems of Disk Arrays Small Writes RAID-5: Small Write Algorithm 1 Logical Write = 2 Physical Reads + 2 Physical Writes D0' D0 D1 D2 D3 P new data old data (1. Read) old parity (2. Read) + XOR + XOR (3. Write) (4. Write) D0' D1 D2 D3 P' 34

35 RAID Levels 4/21/11 CSE325 - Storage 35

36 RAID (0 + 1) and (1 + 0) 4/21/11 CSE325 - Storage 36

37 Operating System Issues Major OS jobs are to manage physical devices and to present a virtual machine abstraction to applications For hard disks, the OS provides two abstraction: Raw device an array of data blocks. File system the OS queues and schedules the interleaved requests from several applications. 4/21/11 CSE325 - Storage 37

Module 13: Secondary-Storage Structure

Module 13: Secondary-Storage Structure Module 13: Secondary-Storage Structure Disk Structure Disk Scheduling Disk Management Swap-Space Management Disk Reliability Stable-Storage Implementation Operating System Concepts 13.1 Silberschatz and

More information

Chapter 14: Mass-Storage Systems. Disk Structure

Chapter 14: Mass-Storage Systems. Disk Structure 1 Chapter 14: Mass-Storage Systems Disk Structure Disk Scheduling Disk Management Swap-Space Management RAID Structure Disk Attachment Stable-Storage Implementation Tertiary Storage Devices Operating System

More information

Disk Scheduling. Based on the slides supporting the text

Disk Scheduling. Based on the slides supporting the text Disk Scheduling Based on the slides supporting the text 1 User-Space I/O Software Layers of the I/O system and the main functions of each layer 2 Disk Structure Disk drives are addressed as large 1-dimensional

More information

Disk Scheduling. Chapter 14 Based on the slides supporting the text and B.Ramamurthy s slides from Spring 2001

Disk Scheduling. Chapter 14 Based on the slides supporting the text and B.Ramamurthy s slides from Spring 2001 Disk Scheduling Chapter 14 Based on the slides supporting the text and B.Ramamurthy s slides from Spring 2001 1 User-Space I/O Software Layers of the I/O system and the main functions of each layer 2 Disks

More information

Chapter 13: Mass-Storage Systems. Disk Scheduling. Disk Scheduling (Cont.) Disk Structure FCFS. Moving-Head Disk Mechanism

Chapter 13: Mass-Storage Systems. Disk Scheduling. Disk Scheduling (Cont.) Disk Structure FCFS. Moving-Head Disk Mechanism Chapter 13: Mass-Storage Systems Disk Scheduling Disk Structure Disk Scheduling Disk Management Swap-Space Management RAID Structure Disk Attachment Stable-Storage Implementation Tertiary Storage Devices

More information

Chapter 13: Mass-Storage Systems. Disk Structure

Chapter 13: Mass-Storage Systems. Disk Structure Chapter 13: Mass-Storage Systems Disk Structure Disk Scheduling Disk Management Swap-Space Management RAID Structure Disk Attachment Stable-Storage Implementation Tertiary Storage Devices Operating System

More information

Chapter 12: Mass-Storage Systems. Operating System Concepts 8 th Edition,

Chapter 12: Mass-Storage Systems. Operating System Concepts 8 th Edition, Chapter 12: Mass-Storage Systems, Silberschatz, Galvin and Gagne 2009 Chapter 12: Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk Scheduling 12.2 Silberschatz, Galvin and Gagne

More information

CS3600 SYSTEMS AND NETWORKS

CS3600 SYSTEMS AND NETWORKS CS3600 SYSTEMS AND NETWORKS NORTHEASTERN UNIVERSITY Lecture 9: Mass Storage Structure Prof. Alan Mislove (amislove@ccs.neu.edu) Moving-head Disk Mechanism 2 Overview of Mass Storage Structure Magnetic

More information

Chapter 10: Mass-Storage Systems

Chapter 10: Mass-Storage Systems Chapter 10: Mass-Storage Systems Silberschatz, Galvin and Gagne Overview of Mass Storage Structure Magnetic disks provide bulk of secondary storage of modern computers Drives rotate at 60 to 200 times

More information

Tape pictures. CSE 30341: Operating Systems Principles

Tape pictures. CSE 30341: Operating Systems Principles Tape pictures 4/11/07 CSE 30341: Operating Systems Principles page 1 Tape Drives The basic operations for a tape drive differ from those of a disk drive. locate positions the tape to a specific logical

More information

V. Mass Storage Systems

V. Mass Storage Systems TDIU25: Operating Systems V. Mass Storage Systems SGG9: chapter 12 o Mass storage: Hard disks, structure, scheduling, RAID Copyright Notice: The lecture notes are mainly based on modifications of the slides

More information

Chapter 10: Mass-Storage Systems

Chapter 10: Mass-Storage Systems Chapter 10: Mass-Storage Systems 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

More information

Chapter 10: Mass-Storage Systems. Operating System Concepts 9 th Edition

Chapter 10: Mass-Storage Systems. Operating System Concepts 9 th Edition Chapter 10: Mass-Storage Systems 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

More information

Chapter 12: Mass-Storage Systems. Operating System Concepts 8 th Edition,

Chapter 12: Mass-Storage Systems. Operating System Concepts 8 th Edition, Chapter 12: Mass-Storage Systems, Silberschatz, Galvin and Gagne 2009 Chapter 12: Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk Management

More information

Chapter 12: Secondary-Storage Structure. Operating System Concepts 8 th Edition,

Chapter 12: Secondary-Storage Structure. Operating System Concepts 8 th Edition, Chapter 12: Secondary-Storage Structure, Silberschatz, Galvin and Gagne 2009 Chapter 12: Secondary-Storage Structure Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk

More information

Chapter 14: Mass-Storage Systems

Chapter 14: Mass-Storage Systems Chapter 14: Mass-Storage Systems Disk Structure Disk Scheduling Disk Management Swap-Space Management RAID Structure Disk Attachment Stable-Storage Implementation Tertiary Storage Devices Operating System

More information

Module 13: Secondary-Storage

Module 13: Secondary-Storage Module 13: Secondary-Storage Disk Structure Disk Scheduling Disk Management Swap-Space Management Disk Reliability Stable-Storage Implementation Tertiary Storage Devices Operating System Issues Performance

More information

Chapter 12: Mass-Storage

Chapter 12: Mass-Storage Chapter 12: Mass-Storage Systems Chapter 12: Mass-Storage Systems Revised 2010. Tao Yang Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk Management Swap-Space Management

More information

Che-Wei Chang Department of Computer Science and Information Engineering, Chang Gung University

Che-Wei Chang Department of Computer Science and Information Engineering, Chang Gung University Che-Wei Chang chewei@mail.cgu.edu.tw Department of Computer Science and Information Engineering, Chang Gung University l Chapter 10: File System l Chapter 11: Implementing File-Systems l Chapter 12: Mass-Storage

More information

I/O, Disks, and RAID Yi Shi Fall Xi an Jiaotong University

I/O, Disks, and RAID Yi Shi Fall Xi an Jiaotong University I/O, Disks, and RAID Yi Shi Fall 2017 Xi an Jiaotong University Goals for Today Disks How does a computer system permanently store data? RAID How to make storage both efficient and reliable? 2 What does

More information

Mass-Storage Structure

Mass-Storage Structure CS 4410 Operating Systems Mass-Storage Structure Summer 2011 Cornell University 1 Today How is data saved in the hard disk? Magnetic disk Disk speed parameters Disk Scheduling RAID Structure 2 Secondary

More information

EIDE, ATA, SATA, USB,

EIDE, ATA, SATA, USB, 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

More information

Overview of Mass Storage Structure

Overview of Mass Storage Structure CSC 4103 - Operating Systems Spring 2008 Lecture - XVIII Mass Storage & IO Tevfik Ko!ar Louisiana State University April 8th, 2008 1 Overview of Mass Storage Structure Magnetic disks provide bulk of secondary

More information

MASS-STORAGE STRUCTURE

MASS-STORAGE STRUCTURE UNIT IV MASS-STORAGE STRUCTURE Mass-Storage Systems ndescribe the physical structure of secondary and tertiary storage devices and the resulting effects on the uses of the devicesnexplain the performance

More information

CS420: Operating Systems. Mass Storage Structure

CS420: Operating Systems. Mass Storage Structure Mass Storage Structure James Moscola Department of Physical Sciences York College of Pennsylvania Based on Operating System Concepts, 9th Edition by Silberschatz, Galvin, Gagne Overview of Mass Storage

More information

Mass-Storage Structure

Mass-Storage Structure Operating Systems (Fall/Winter 2018) Mass-Storage Structure Yajin Zhou (http://yajin.org) Zhejiang University Acknowledgement: some pages are based on the slides from Zhi Wang(fsu). Review On-disk structure

More information

CS370 Operating Systems

CS370 Operating Systems CS370 Operating Systems Colorado State University Yashwant K Malaiya Spring 2018 Lecture 24 Mass Storage, HDFS/Hadoop Slides based on Text by Silberschatz, Galvin, Gagne Various sources 1 1 FAQ What 2

More information

Chapter 14: Mass-Storage Systems

Chapter 14: Mass-Storage Systems Chapter 14: Mass-Storage Systems Disk Structure Disk Scheduling Disk Management Swap-Space Management RAID Structure Disk Attachment Stable-Storage Implementation Tertiary Storage Devices Operating System

More information

Free Space Management

Free Space Management CSC 4103 - Operating Systems Spring 2007 Lecture - XVI File Systems - II Tevfik Koşar Louisiana State University March 22 nd, 2007 1 Free Space Management Disk space limited Need to re-use the space from

More information

CHAPTER 12: MASS-STORAGE SYSTEMS (A) By I-Chen Lin Textbook: Operating System Concepts 9th Ed.

CHAPTER 12: MASS-STORAGE SYSTEMS (A) By I-Chen Lin Textbook: Operating System Concepts 9th Ed. CHAPTER 12: MASS-STORAGE SYSTEMS (A) By I-Chen Lin Textbook: Operating System Concepts 9th Ed. Chapter 12: Mass-Storage Systems Overview of Mass-Storage Structure Disk Structure Disk Attachment Disk Scheduling

More information

Chapter 10: Mass-Storage Systems

Chapter 10: Mass-Storage Systems COP 4610: Introduction to Operating Systems (Spring 2016) Chapter 10: Mass-Storage Systems Zhi Wang Florida State University Content Overview of Mass Storage Structure Disk Structure Disk Scheduling Disk

More information

Chapter 14 Mass-Storage Structure

Chapter 14 Mass-Storage Structure Chapter 14 Mass-Storage Structure 1 Outline Disk Structure Disk Scheduling Disk Management Swap-Space Management RAID Structure Disk Attachment Stable-Storage Implementation Tertiary Storage Devices 2

More information

File. File System Implementation. Operations. Permissions and Data Layout. Storing and Accessing File Data. Opening a File

File. File System Implementation. Operations. Permissions and Data Layout. Storing and Accessing File Data. Opening a File File File System Implementation Operating Systems Hebrew University Spring 2007 Sequence of bytes, with no structure as far as the operating system is concerned. The only operations are to read and write

More information

Silberschatz, et al. Topics based on Chapter 13

Silberschatz, et al. Topics based on Chapter 13 Silberschatz, et al. Topics based on Chapter 13 Mass Storage Structure CPSC 410--Richard Furuta 3/23/00 1 Mass Storage Topics Secondary storage structure Disk Structure Disk Scheduling Disk Management

More information

Chapter 10: Mass-Storage Systems. Operating System Concepts 9 th Edition

Chapter 10: Mass-Storage Systems. Operating System Concepts 9 th Edition Chapter 10: Mass-Storage Systems 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

More information

Disk scheduling Disk reliability Tertiary storage Swap space management Linux swap space management

Disk scheduling Disk reliability Tertiary storage Swap space management Linux swap space management Lecture Overview Mass storage devices Disk scheduling Disk reliability Tertiary storage Swap space management Linux swap space management Operating Systems - June 28, 2001 Disk Structure Disk drives are

More information

Lecture 9. I/O Management and Disk Scheduling Algorithms

Lecture 9. I/O Management and Disk Scheduling Algorithms Lecture 9 I/O Management and Disk Scheduling Algorithms 1 Lecture Contents 1. I/O Devices 2. Operating System Design Issues 3. Disk Scheduling Algorithms 4. RAID (Redundant Array of Independent Disks)

More information

Chapter 12: Mass-Storage

Chapter 12: Mass-Storage hapter 12: Mass-Storage Systems hapter 12: Mass-Storage Systems To explain the performance characteristics of mass-storage devices To evaluate disk scheduling algorithms To discuss operating-system services

More information

Chapter 12: Mass-Storage

Chapter 12: Mass-Storage hapter 12: Mass-Storage Systems hapter 12: Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk Management RAID Structure Objectives Moving-head Disk

More information

Chapter 12: Mass-Storage Systems. Operating System Concepts 8 th Edition

Chapter 12: Mass-Storage Systems. Operating System Concepts 8 th Edition Chapter 12: Mass-Storage Systems Silberschatz, Galvin and Gagne 2009 Chapter 12: Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk Management Swap-Space

More information

Chapter 11: Mass-Storage Systems

Chapter 11: Mass-Storage Systems Chapter 11: Mass-Storage Systems Chapter 11: Mass-Storage Systems Overview of Mass Storage Structure" Disk Structure" Disk Attachment" Disk Scheduling" Disk Management" Swap-Space Management" RAID Structure"

More information

EI 338: Computer Systems Engineering (Operating Systems & Computer Architecture)

EI 338: Computer Systems Engineering (Operating Systems & Computer Architecture) EI 338: Computer Systems Engineering (Operating Systems & Computer Architecture) Dept. of Computer Science & Engineering Chentao Wu wuct@cs.sjtu.edu.cn Download lectures ftp://public.sjtu.edu.cn User:

More information

Chapter 12: Mass-Storage Systems. Operating System Concepts 9 th Edition

Chapter 12: Mass-Storage Systems. Operating System Concepts 9 th Edition Chapter 12: Mass-Storage Systems Silberschatz, Galvin and Gagne 2013 Chapter 12: Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk Management Swap-Space

More information

I/O Systems and Storage Devices

I/O Systems and Storage Devices CSC 256/456: Operating Systems I/O Systems and Storage Devices John Criswell! University of Rochester 1 I/O Device Controllers I/O devices have both mechanical component & electronic component! The electronic

More information

Chapter 5: Input Output Management. Slides by: Ms. Shree Jaswal

Chapter 5: Input Output Management. Slides by: Ms. Shree Jaswal : Input Output Management Slides by: Ms. Shree Jaswal Topics as per syllabus I/O Devices, Organization of the I/O Function, Operating System Design Issues, I/O Buffering, Disk Scheduling and disk scheduling

More information

OPERATING SYSTEMS CS3502 Spring Input/Output System Chapter 9

OPERATING SYSTEMS CS3502 Spring Input/Output System Chapter 9 OPERATING SYSTEMS CS3502 Spring 2018 Input/Output System Chapter 9 Input/Output System Major objectives: An application s I/O requests are sent to the I/O device. Take whatever response comes back from

More information

Part IV I/O System. Chapter 12: Mass Storage Structure

Part IV I/O System. Chapter 12: Mass Storage Structure Part IV I/O System Chapter 12: Mass Storage Structure Disk Structure Three elements: cylinder, track and sector/block. Three types of latency (i.e., delay) Positional or seek delay mechanical and slowest

More information

Operating Systems 2010/2011

Operating Systems 2010/2011 Operating Systems 2010/2011 Input/Output Systems part 2 (ch13, ch12) Shudong Chen 1 Recap Discuss the principles of I/O hardware and its complexity Explore the structure of an operating system s I/O subsystem

More information

Mass-Storage. ICS332 - Fall 2017 Operating Systems. Henri Casanova

Mass-Storage. ICS332 - Fall 2017 Operating Systems. Henri Casanova Mass-Storage ICS332 - Fall 2017 Operating Systems Henri Casanova (henric@hawaii.edu) Magnetic Disks! Magnetic disks (a.k.a. hard drives ) are (still) the most common secondary storage devices today! They

More information

File. File System Implementation. File Metadata. File System Implementation. Direct Memory Access Cont. Hardware background: Direct Memory Access

File. File System Implementation. File Metadata. File System Implementation. Direct Memory Access Cont. Hardware background: Direct Memory Access File File System Implementation Operating Systems Hebrew University Spring 2009 Sequence of bytes, with no structure as far as the operating system is concerned. The only operations are to read and write

More information

Chapter 12: Mass-Storage Systems

Chapter 12: Mass-Storage Systems Chapter 12: Mass-Storage Systems Chapter 12: Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk Management Swap-Space Management RAID Structure

More information

CHAPTER 12 AND 13 - MASS-STORAGE STRUCTURE & I/O- SYSTEMS

CHAPTER 12 AND 13 - MASS-STORAGE STRUCTURE & I/O- SYSTEMS CHAPTER 12 AND 13 - MASS-STORAGE STRUCTURE & I/O- SYSTEMS OBJECTIVES Describe physical structure of secondary storage devices and its effects on the uses of the devices Explain the performance char. of

More information

I/O Device Controllers. I/O Systems. I/O Ports & Memory-Mapped I/O. Direct Memory Access (DMA) Operating Systems 10/20/2010. CSC 256/456 Fall

I/O Device Controllers. I/O Systems. I/O Ports & Memory-Mapped I/O. Direct Memory Access (DMA) Operating Systems 10/20/2010. CSC 256/456 Fall I/O Device Controllers I/O Systems CS 256/456 Dept. of Computer Science, University of Rochester 10/20/2010 CSC 2/456 1 I/O devices have both mechanical component & electronic component The electronic

More information

Mass-Storage Systems. Mass-Storage Systems. Disk Attachment. Disk Attachment

Mass-Storage Systems. Mass-Storage Systems. Disk Attachment. Disk Attachment TDIU11 Operating systems Mass-Storage Systems [SGG7/8/9] Chapter 12 Copyright Notice: The lecture notes are mainly based on Silberschatz s, Galvin s and Gagne s book ( Operating System Copyright Concepts,

More information

Ricardo Rocha. Department of Computer Science Faculty of Sciences University of Porto

Ricardo Rocha. Department of Computer Science Faculty of Sciences University of Porto Ricardo Rocha Department of Computer Science Faculty of Sciences University of Porto Slides based on the book Operating System Concepts, 9th Edition, Abraham Silberschatz, Peter B. Galvin and Greg Gagne,

More information

CS370 Operating Systems

CS370 Operating Systems CS370 Operating Systems Colorado State University Yashwant K Malaiya Fall 2016 Lecture 35 Mass Storage Slides based on Text by Silberschatz, Galvin, Gagne Various sources 1 1 Questions For You Local/Global

More information

Introduction Disks RAID Tertiary storage. Mass Storage. CMSC 420, York College. November 21, 2006

Introduction Disks RAID Tertiary storage. Mass Storage. CMSC 420, York College. November 21, 2006 November 21, 2006 The memory hierarchy Red = Level Access time Capacity Features Registers nanoseconds 100s of bytes fixed Cache nanoseconds 1-2 MB fixed RAM nanoseconds MBs to GBs expandable Disk milliseconds

More information

CS370: System Architecture & Software [Fall 2014] Dept. Of Computer Science, Colorado State University

CS370: System Architecture & Software [Fall 2014] Dept. Of Computer Science, Colorado State University CS 370: SYSTEM ARCHITECTURE & SOFTWARE [DISK SCHEDULING ALGORITHMS] Frequently asked questions from the previous class survey Shrideep Pallickara Computer Science Colorado State University L30.1 L30.2

More information

Mass-Storage. ICS332 Operating Systems

Mass-Storage. ICS332 Operating Systems Mass-Storage ICS332 Operating Systems Magnetic Disks Magnetic disks are (still) the most common secondary storage devices today They are messy Errors, bad blocks, missed seeks, moving parts And yet, the

More information

Disc Allocation and Disc Arm Scheduling?

Disc Allocation and Disc Arm Scheduling? CSE 2431: Introduction to Operating Systems Disc Allocation and Disc Arm Scheduling? Study: 9 th (12.4, 12.5, 10.4) 10 th (14.4, 14.5, 11.2) 11-29-2018 Presentation K Gojko Babić Moving-Head Disk Mechanism

More information

OPERATING SYSTEMS CS3502 Spring Input/Output System Chapter 9

OPERATING SYSTEMS CS3502 Spring Input/Output System Chapter 9 OPERATING SYSTEMS CS3502 Spring 2017 Input/Output System Chapter 9 Input/Output System Major objectives: An application s I/O requests are sent to the I/O device. Take whatever response comes back from

More information

UNIT 4 Device Management

UNIT 4 Device Management UNIT 4 Device Management (A) Device Function. (B) Device Characteristic. (C) Disk space Management. (D) Allocation and Disk scheduling Methods. [4.1] Device Management Functions The management of I/O devices

More information

CSE 120. Operating Systems. March 27, 2014 Lecture 17. Mass Storage. Instructor: Neil Rhodes. Wednesday, March 26, 14

CSE 120. Operating Systems. March 27, 2014 Lecture 17. Mass Storage. Instructor: Neil Rhodes. Wednesday, March 26, 14 CSE 120 Operating Systems March 27, 2014 Lecture 17 Mass Storage Instructor: Neil Rhodes Paging and Translation Lookaside Buffer frame dirty? no yes CPU checks TLB PTE in TLB? Free page frame? no yes OS

More information

UNIVERSITY OF MASSACHUSETTS Dept. of Electrical & Computer Engineering. Computer Architecture ECE 568

UNIVERSITY OF MASSACHUSETTS Dept. of Electrical & Computer Engineering. Computer Architecture ECE 568 UNIVERSITY OF MASSACHUSETTS Dept. of Electrical & Computer Engineering Computer Architecture ECE 568 Part 6 Input/Output Israel Koren ECE568/Koren Part.6. Motivation: Why Care About I/O? CPU Performance:

More information

CS370 Operating Systems

CS370 Operating Systems CS370 Operating Systems Colorado State University Yashwant K Malaiya Spring 2019 L22 File-system Implementation Slides based on Text by Silberschatz, Galvin, Gagne Various sources 1 1 FAQ When is contiguous

More information

CS370: Operating Systems [Spring 2017] Dept. Of Computer Science, Colorado State University

CS370: Operating Systems [Spring 2017] Dept. Of Computer Science, Colorado State University CS 370: OPERATING SYSTEMS [DISK SCHEDULING ALGORITHMS] Shrideep Pallickara Computer Science Colorado State University Frequently asked questions from the previous class survey Can a UNIX file span over

More information

CS370: Operating Systems [Fall 2018] Dept. Of Computer Science, Colorado State University

CS370: Operating Systems [Fall 2018] Dept. Of Computer Science, Colorado State University CS 370: OPERATING SYSTEMS [DISK SCHEDULING ALGORITHMS] Shrideep Pallickara Computer Science Colorado State University L30.1 Frequently asked questions from the previous class survey ECCs: How does it impact

More information

CS370: Operating Systems [Fall 2018] Dept. Of Computer Science, Colorado State University

CS370: Operating Systems [Fall 2018] Dept. Of Computer Science, Colorado State University Frequently asked questions from the previous class survey CS 370: OPERATING SYSTEMS [DISK SCHEDULING ALGORITHMS] Shrideep Pallickara Computer Science Colorado State University ECCs: How does it impact

More information

CS 471 Operating Systems. Yue Cheng. George Mason University Fall 2017

CS 471 Operating Systems. Yue Cheng. George Mason University Fall 2017 CS 471 Operating Systems Yue Cheng George Mason University Fall 2017 Review: Disks 2 Device I/O Protocol Variants o Status checks Polling Interrupts o Data PIO DMA 3 Disks o Doing an disk I/O requires:

More information

CISC 7310X. C11: Mass Storage. Hui Chen Department of Computer & Information Science CUNY Brooklyn College. 4/19/2018 CUNY Brooklyn College

CISC 7310X. C11: Mass Storage. Hui Chen Department of Computer & Information Science CUNY Brooklyn College. 4/19/2018 CUNY Brooklyn College CISC 7310X C11: Mass Storage Hui Chen Department of Computer & Information Science CUNY Brooklyn College 4/19/2018 CUNY Brooklyn College 1 Outline Review of memory hierarchy Mass storage devices Reliability

More information

Part IV I/O System Chapter 1 2: 12: Mass S torage Storage Structur Structur Fall 2010

Part IV I/O System Chapter 1 2: 12: Mass S torage Storage Structur Structur Fall 2010 Part IV I/O System Chapter 12: Mass Storage Structure Fall 2010 1 Disk Structure Three elements: cylinder, track and sector/block. Three types of latency (i.e., delay) Positional or seek delay mechanical

More information

Chapter 7: Mass-storage structure & I/O systems. Operating System Concepts 8 th Edition,

Chapter 7: Mass-storage structure & I/O systems. Operating System Concepts 8 th Edition, Chapter 7: Mass-storage structure & I/O systems, Silberschatz, Galvin and Gagne 2009 Mass-storage structure & I/O systems Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling

More information

UNIT-7. Overview of Mass Storage Structure

UNIT-7. Overview of Mass Storage Structure Overview of Mass Storage Structure UNIT-7 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

More information

Operating Systems. Mass-Storage Structure Based on Ch of OS Concepts by SGG

Operating Systems. Mass-Storage Structure Based on Ch of OS Concepts by SGG Operating Systems Mass-Storage Structure Based on Ch. 10-11 of OS Concepts by SGG Mass Storage Devices Disks A r/w head flies above the spinning disk Each disk is divided into tracks and each track in

More information

CS370: System Architecture & Software [Fall 2014] Dept. Of Computer Science, Colorado State University

CS370: System Architecture & Software [Fall 2014] Dept. Of Computer Science, Colorado State University CS 370: SYSTEM ARCHITECTURE & SOFTWARE [MASS STORAGE] Frequently asked questions from the previous class survey Shrideep Pallickara Computer Science Colorado State University L29.1 L29.2 Topics covered

More information

Computer Science 146. Computer Architecture

Computer Science 146. Computer Architecture Computer Science 46 Computer Architecture Spring 24 Harvard University Instructor: Prof dbrooks@eecsharvardedu Lecture 22: More I/O Computer Science 46 Lecture Outline HW5 and Project Questions? Storage

More information

UNIVERSITY OF MASSACHUSETTS Dept. of Electrical & Computer Engineering. Computer Architecture ECE 568

UNIVERSITY OF MASSACHUSETTS Dept. of Electrical & Computer Engineering. Computer Architecture ECE 568 UNIVERSITY OF MASSACHUSETTS Dept. of Electrical & Computer Engineering Computer Architecture ECE 568 Part 6 Input/Output Israel Koren ECE568/Koren Part.6. CPU performance keeps increasing 26 72-core Xeon

More information

Overview of Mass Storage Structure

Overview of Mass Storage Structure Overview of Mass Storage Structure Magnetic disks provide bulk of secondary storage Drives rotate at 70 to 250 times per second Ipod disks: 4200 rpm Laptop disks: 4200, 5400 rpm or 7200 rpm Desktop disks:

More information

CSCI-GA Operating Systems. I/O : Disk Scheduling and RAID. Hubertus Franke

CSCI-GA Operating Systems. I/O : Disk Scheduling and RAID. Hubertus Franke CSCI-GA.2250-001 Operating Systems I/O : Disk Scheduling and RAID Hubertus Franke frankeh@cs.nyu.edu Disks Scheduling Abstracted by OS as files A Conventional Hard Disk (Magnetic) Structure Hard Disk

More information

Definition of RAID Levels

Definition of RAID Levels RAID The basic idea of RAID (Redundant Array of Independent Disks) is to combine multiple inexpensive disk drives into an array of disk drives to obtain performance, capacity and reliability that exceeds

More information

CS2410: Computer Architecture. Storage systems. Sangyeun Cho. Computer Science Department University of Pittsburgh

CS2410: Computer Architecture. Storage systems. Sangyeun Cho. Computer Science Department University of Pittsburgh CS24: Computer Architecture Storage systems Sangyeun Cho Computer Science Department (Some slides borrowed from D Patterson s lecture slides) Case for storage Shift in focus from computation to communication

More information

I/O Management and Disk Scheduling. Chapter 11

I/O Management and Disk Scheduling. Chapter 11 I/O Management and Disk Scheduling Chapter 11 Categories of I/O Devices Human readable used to communicate with the user video display terminals keyboard mouse printer Categories of I/O Devices Machine

More information

Today: Coda, xfs! Brief overview of other file systems. Distributed File System Requirements!

Today: Coda, xfs! Brief overview of other file systems. Distributed File System Requirements! Today: Coda, xfs! Case Study: Coda File System Brief overview of other file systems xfs Log structured file systems Lecture 21, page 1 Distributed File System Requirements! Transparency Access, location,

More information

CSE 380 Computer Operating Systems

CSE 380 Computer Operating Systems CSE 380 Computer Operating Systems Instructor: Insup Lee University of Pennsylvania Fall 2003 Lecture Note on Disk I/O 1 I/O Devices Storage devices Floppy, Magnetic disk, Magnetic tape, CD-ROM, DVD User

More information

Chapter-6. SUBJECT:- Operating System TOPICS:- I/O Management. Created by : - Sanjay Patel

Chapter-6. SUBJECT:- Operating System TOPICS:- I/O Management. Created by : - Sanjay Patel Chapter-6 SUBJECT:- Operating System TOPICS:- I/O Management Created by : - Sanjay Patel Disk Scheduling Algorithm 1) First-In-First-Out (FIFO) 2) Shortest Service Time First (SSTF) 3) SCAN 4) Circular-SCAN

More information

Today: Secondary Storage! Typical Disk Parameters!

Today: Secondary Storage! Typical Disk Parameters! Today: Secondary Storage! To read or write a disk block: Seek: (latency) position head over a track/cylinder. The seek time depends on how fast the hardware moves the arm. Rotational delay: (latency) time

More information

CSE Opera+ng System Principles

CSE Opera+ng System Principles CSE 30341 Opera+ng System rinciples Mass Storage Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk AGachment Disk Scheduling Disk Management Swap-Space Management RAID Structure

More information

Mass-Storage Systems

Mass-Storage Systems CS307 Mass-Storage Systems Fan Wu Department of Computer Science and Engineering Shanghai Jiao Tong University Spring 2018 The First Commercial Disk Drive 1956 IBM RAMDAC computer included the IBM Model

More information

Disks and RAID. CS 4410 Operating Systems. [R. Agarwal, L. Alvisi, A. Bracy, E. Sirer, R. Van Renesse]

Disks and RAID. CS 4410 Operating Systems. [R. Agarwal, L. Alvisi, A. Bracy, E. Sirer, R. Van Renesse] Disks and RAID CS 4410 Operating Systems [R. Agarwal, L. Alvisi, A. Bracy, E. Sirer, R. Van Renesse] Storage Devices Magnetic disks Storage that rarely becomes corrupted Large capacity at low cost Block

More information

UNIVERSITY OF MASSACHUSETTS Dept. of Electrical & Computer Engineering. Computer Architecture ECE 568

UNIVERSITY OF MASSACHUSETTS Dept. of Electrical & Computer Engineering. Computer Architecture ECE 568 UNIVERSITY OF MASSACHUSETTS Dept of Electrical & Computer Engineering Computer Architecture ECE 568 art 5 Input/Output Israel Koren ECE568/Koren art5 CU performance keeps increasing 26 72-core Xeon hi

More information

Physical Storage Media

Physical Storage Media Physical Storage Media These slides are a modified version of the slides of the book Database System Concepts, 5th Ed., McGraw-Hill, by Silberschatz, Korth and Sudarshan. Original slides are available

More information

CSE380 - Operating Systems. Communicating with Devices

CSE380 - Operating Systems. Communicating with Devices CSE380 - Operating Systems Notes for Lecture 15-11/4/04 Matt Blaze (some examples by Insup Lee) Communicating with Devices Modern architectures support convenient communication with devices memory mapped

More information

Operating System 1 (ECS-501)

Operating System 1 (ECS-501) Operating System 1 (ECS-501) 1. Mass Storage Structure: 1.1 Disk Structure: Unit- V I/O Management & Disk Scheduling A. Magnetic disks provide bulk of secondary storage of modern computers Drives rotate

More information

Chapter 11 I/O Management and Disk Scheduling

Chapter 11 I/O Management and Disk Scheduling Operating Systems: Internals and Design Principles, 6/E William Stallings Chapter 11 I/O Management and Disk Scheduling Patricia Roy Manatee Community College, Venice, FL 2008, Prentice Hall 1 2 Differences

More information

Operating Systems. No. 9 ศร ณย อ นทโกส ม Sarun Intakosum

Operating Systems. No. 9 ศร ณย อ นทโกส ม Sarun Intakosum Operating Systems No. 9 ศร ณย อ นทโกส ม Sarun Intakosum 1 Virtual-Memory Management 2 Background Virtual memory separation of user logical memory from physical memory. Only part of the program needs to

More information

Chapter 11. I/O Management and Disk Scheduling

Chapter 11. I/O Management and Disk Scheduling Operating System Chapter 11. I/O Management and Disk Scheduling Lynn Choi School of Electrical Engineering Categories of I/O Devices I/O devices can be grouped into 3 categories Human readable devices

More information

Lecture 23: Storage Systems. Topics: disk access, bus design, evaluation metrics, RAID (Sections )

Lecture 23: Storage Systems. Topics: disk access, bus design, evaluation metrics, RAID (Sections ) Lecture 23: Storage Systems Topics: disk access, bus design, evaluation metrics, RAID (Sections 7.1-7.9) 1 Role of I/O Activities external to the CPU are typically orders of magnitude slower Example: while

More information

Lecture 23: I/O Redundant Arrays of Inexpensive Disks Professor Randy H. Katz Computer Science 252 Spring 1996

Lecture 23: I/O Redundant Arrays of Inexpensive Disks Professor Randy H. Katz Computer Science 252 Spring 1996 Lecture 23: I/O Redundant Arrays of Inexpensive Disks Professor Randy H Katz Computer Science 252 Spring 996 RHKS96 Review: Storage System Issues Historical Context of Storage I/O Storage I/O Performance

More information

Administrivia. CMSC 411 Computer Systems Architecture Lecture 19 Storage Systems, cont. Disks (cont.) Disks - review

Administrivia. CMSC 411 Computer Systems Architecture Lecture 19 Storage Systems, cont. Disks (cont.) Disks - review Administrivia CMSC 411 Computer Systems Architecture Lecture 19 Storage Systems, cont. Homework #4 due Thursday answers posted soon after Exam #2 on Thursday, April 24 on memory hierarchy (Unit 4) and

More information

Lecture 29. Friday, March 23 CS 470 Operating Systems - Lecture 29 1

Lecture 29. Friday, March 23 CS 470 Operating Systems - Lecture 29 1 Lecture 29 Reminder: Homework 7 is due on Monday at class time for Exam 2 review; no late work accepted. Reminder: Exam 2 is on Wednesday. Exam 2 review sheet is posted. Questions? Friday, March 23 CS

More information