ikh311-07
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This document discusses input/output (I/O) concepts in operating systems. It covers I/O devices and controllers, principles of I/O software including device independence and uniform naming. Memory-mapped I/O, direct memory access, and interrupts are described. Page replacement algorithms like not recently used and first-in first-out are introduced. The document also examines disk hardware components, formatting, and scheduling algorithms. Error handling and stable storage concepts for disks are summarized. References for further reading on operating system concepts are provided.
ikh311-07
- 1. Sistem Operasi IKH311 Masukan Luaran (Input/Output)
- 2. Prinsip I/O 2
- 3. Device Controllers I/O devices have components: ● mechanical component ● electronic component The electronic component is the device controller ● may be able to handle multiple devices Controller's tasks ● convert serial bit stream to block of bytes ● perform error correction as necessary ● make available to main memory
- 4. Principles of I/O Software Goals of I/O Software (1) Device independence ● programs can access any I/O device ● without specifying device in advance – (floppy, hard drive, or CD-ROM) Uniform naming ● name of a file or device a string or an integer ● not depending on
- 7. Direct Memory Access (DMA)
- 8. Interrupt
- 9. Not Recently Used Page Replacement Algorithm Each page has Reference bit, Modified bit bits are set when page is referenced, modified Pages are classified not referenced, not modified not referenced, modified
- 10. Device-Independent I/O Software (1) Uniform interfacing for device drivers Buffering Error reporting Allocating and releasing dedicate devices Providing a deice-independent block size Functions of the device-independent I/O software 10
- 11. FIFO Page Replacement Algorithm Maintain a linked list of all pages in order they came into memory Page at beginning of list replaced Disadvantage page in memory the longest may be often used
- 12. Device-Independent I/O Software (3) (a) Unbuffered input (b) Buffering in user space (c) Buffering in the kernel followed by copying to user space (d) Double buffering in the kernel 12
- 13. Device-Independent I/O Software (4) Networking may involve many copies 13
- 14. Disks Disk Hardware (1) Disk parameters for the original IBM PC floppy disk 14 and a Western Digital WD 18300 hard disk
- 15. Disk Hardware (2) Physical geometry of a disk with two zones A possible virtual geometry for this disk 15
- 16. Disk Hardware (3) Raid levels 0 through 2 Backup and parity drives are shaded 16
- 17. Disk Hardware (4) Raid levels 3 through 5 Backup and parity drives are shaded 17
- 18. Disk Hardware (5) Recording structure of a CD or CD-ROM 18
- 19. Disk Hardware (6) Logical data layout on a CD-ROM 19
- 20. Disk Hardware (7) Cross section of a CD-R disk and laser ● not to scale Silver CD-ROM has similar structure ● without dye layer ● with pitted aluminum layer instead of gold 20
- 21. Disk Hardware (8) A double sided, dual layer DVD disk 21
- 22. Disk Formatting (1) A disk sector 22
- 23. Disk Formatting (2) An illustration of cylinder skew 23
- 24. Disk Formatting (3) No interleaving Single interleaving Double interleaving 24
- 25. Disk Arm Scheduling Algorithms (1) • Time required to read or write a disk block determined by 3 factors 1. Seek time 2. Rotational delay 3. Actual transfer time • Seek time dominates • Error checking is done by controllers 25
- 26. Disk Arm Scheduling Algorithms (2) Initial Pending position requests Shortest Seek First (SSF) disk scheduling algorithm 26
- 27. Disk Arm Scheduling Algorithms (3) The elevator algorithm for scheduling disk requests 27
- 28. Error Handling A disk track with a bad sector Substituting a spare for the bad sector Shifting all the sectors to bypass the bad one 28
- 29. Stable Storage Analysis of the influence of crashes on stable writes 29
- 30. Pustaka Avi Silberschatz, "Operating System Concepts" http://codex.cs.yale.edu/avi/os- book/OS8/os8j/index.html Andrew Tanenbaum, "Modern Operating Systems" http://www.cs.vu.nl/~ast/books/mos2/ Harvey Deitel, "Operating Systems" http://cs.nyu.edu/~yap/classes/os/resources/origin_of _PV.html tjerdastangkas.blogspot.com/search/label/ikh311