1 / 24

Physical Disks

Physical Disks. Module 2.3. Physical Disks. After completing this module, you will be able to: Describe the major physical components of a disk drive and their function Define the logical constructs of a physical disk

Jims
Download Presentation

Physical Disks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Physical Disks Module 2.3

  2. Physical Disks After completing this module, you will be able to: • Describe the major physical components of a disk drive and their function • Define the logical constructs of a physical disk • Describe the access characteristics for disk drives and their performance implications • Describe the logical partitioning of physical drives Module TitlePhysical Disks

  3. Lesson: Disk Drive Components Upon completion of this lesson, you will be able to: • Describe the physical components of a disk drive • Describe the physical structure of a disk drive platter • Discuss how the geometry of a disk impacts how data is recorded on a platter • Differentiate between the logical organization of data and the physical organization on a disk drive Module TitlePhysical Disks

  4. Disk Drive Components: Platters 01010100111010101010 00110100111010101010 00110100111010101010 10110101011010101010 Module TitlePhysical Disks

  5. Disk Drive Components: Spindle Spindle Platters Module TitlePhysical Disks

  6. Disk Drive Components: Read/Write Heads Module TitlePhysical Disks

  7. Disk Drive Components: Actuator Spindle Actuator Module TitlePhysical Disks

  8. Physical Disk Structures: Actuator Arm Assembly R/W Head R/W Head Actuator Module TitlePhysical Disks

  9. Disk Drive Components: Controller Controller Interface HDA Power Connector Bottom View of Disk Drive Module TitlePhysical Disks

  10. Physical Disk Structures: Sectors and Tracks Sector Track Platter Module TitlePhysical Disks

  11. Platter Geometry and Zoned-Bit Recording Sector Track Platter Without Zones Platter With Zones Module TitlePhysical Disks

  12. Physical Disk Structures: Cylinders Cylinder Tracks, Cylinders and Sectors Module TitlePhysical Disks

  13. Sector Cylinder Logical Block Addressing Block 0 Head Block 8 (lower surface) Block 16 Block 32 Block 48 Physical Address = CHS Logical Block Address = Block # Module TitlePhysical Disks

  14. D What the Host Sees A A B C One Logical Volume Multiple Logical Volumes Module TitlePhysical Disks

  15. Lesson Summary Key points covered in this lesson: • Physical drives are made up of: • HDA • Platters connected via a spindle • Read/write heads which are positioned by an actuator • Controller • Controls power, communication, positioning, and optimization • Data is structured on a drive using tracks, sectors, and cylinders • The geometry of a disk impacts how data is recorded on a platter Module TitlePhysical Disks

  16. Lesson: Disk Drive Performance Upon completion of this lesson, you will be able to: • Describe the factors that impact the performance of a drive • Describe how drive reliability is measured Module TitlePhysical Disks

  17. Disk Drive Performance: Positioning • Seek time is the time for read/write heads to move between tracks • Seek time specifications include: • Full stroke • Average • Track-to-track Module TitlePhysical Disks

  18. Disk Drive Performance: Rotational Speed/Latency Module TitlePhysical Disks

  19. Disk Drive Performance: Command Queuing Without Command Queuing Request 1 Request 2 2 4 3 2 1 1 Request 3 3 Request 4 4 With Command Queuing Request 1 Request 2 2 4 2 3 1 1 Request 3 3 Request 4 4 Module TitlePhysical Disks

  20. Buffer Interface HBA Disk Drive Performance: Data Transfer Rate External transfer rate measured here Internal transfer rate measured here Disk Drive Module TitlePhysical Disks

  21. Drive Reliability: MTBF • Mean Time Between Failure • Amount of time that one can anticipate a device to work before an incapacitating malfunction occurs • Based on averages • Measured in hours • Determined by artificially aging the product Module TitlePhysical Disks

  22. Lesson Summary Key points covered in this lesson: • Drive performance is impacted by a number of factors including: • Seek time • Rotational latency • Command queuing • Data transfer rate • Drive reliability is measured using MTBF Module TitlePhysical Disks

  23. Module Summary Key points covered in this module: • Physical drives are made up of a number of components • HDA – houses the platters, spindles, actuator assemblies (which include the actuator and the read/write heads) • Controller - Controls power, communication, positioning, and optimization • Data is structured on a drive using tracks, sectors, and cylinders • Drive performance is impacted by seek time, rotational latency, command queuing, and data transfer rate Module TitlePhysical Disks

  24. Check Your Knowledge • Describe the purpose of the actuator, the read/write head, and the controller on a drive. • What is the difference between a track, a sector, and a cylinder? • Why is zoned-bit recording used? • What is the difference between seek time and rotational latency? • What is the difference between internal and external data transfer rates? • What purpose does the MTBF specification serve? Module TitlePhysical Disks

More Related