A Guide to Managing and Maintaining your PC, 6e

1
A Guide to Managing and Maintaining your PC, 6e

• Chapter 8
• Hard Drives

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Objectives

• Learn how the organization of data on floppy
  drives and hard drives is similar
• Learn about hard drive technologies
• Learn how a computer communicates with a hard
  drive
• Learn how to install a hard drive
• Learn how to solve hard drive problems

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Introduction

• Hard drive most important secondary storage
  device
• Hard drive technologies have evolved rapidly
• Hard drive capacities and speeds have increased
• Interfaces with the computer have also changed
• Floppy disk will be presented before hard drives
• Floppy disk is logically organized like a hard
  drive
• Practical applications
• Managing problems occurring during drive
  installation
• Troubleshooting hard drives after installation

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Learning from Floppy Drives

• Floppy drives are an obsolescent technology
• Replacements CD drives and USB flash memory
• Good reasons for studying floppy drive technology
• Developing support skills for legacy applications
  
• Building a foundation for hard drive support
  skill set

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How Floppy Drives Work

• Main memory is organized logically and physically
• Secondary storage devices are similarly organized
• Physical storage how data is written to media
• Logical storage how OS and BIOS view stored data
• How data is physically stored on a floppy disk
• Two types of floppy disk 5 ¼ inch or 3 ½ inch
• Subsystem drive, 34-pin cable, connector, power
  cord
• Formatting marking tracks and sectors on a disk
• Magnetic read/write heads read/write binary 1s
  and 0s
• Heads attach to actuator arm that moves over
  surface

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Figure 8-4 3 1 -inch, high-density floppy disk
showing tracks and sectors
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Figure 8-5 Inside a floppy disk drive
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How Floppy Drives Work (continued)

• How data is logically stored on a floppy disk
• Floppy drives are always formatted using FAT12
• Cluster (file allocation unit) smallest grouping
  of sectors
• The BIOS manages the disk as a set of physical
  sectors
• OS treats the disk as list of clusters (file
  allocation table)
• A 3 ½ inch high density floppy disk has 2880
  clusters
• A cluster contains one sector, which contains 512
  bytes
• Format floppy disk using Format or Windows
  Explorer
• Structures and features added to the disk
• Tracks, sectors, boot record, two FATs, root
  directory

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Figure 8-6 Clusters, or file allocation units,
are managed by the OS in the file allocation
table, but BIOS manages these clusters as one or
two physical sectors on the disk
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How to Install a Floppy Drive

• It is more cost-effective to replace than repair
  a drive
• A simple seven-step installation procedure
• 1. Turn off computer, unplug power cord, remove
  cover
• 2. Unplug the power cable to the old floppy drive
• 3. Unscrew and dismount the drive
• 4. Slide the new drive into the bay
• 5. If drive is new, connect data cable to
  motherboard
• 6. Connect data cable and power cord to drive
• 7. Replace the cover, turn on computer, verify
  status

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Figure 8-8 Connect colored edge of cable to pin 1
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How Hard Drives Work

• Components of a hard drive
• One, two, or more platters (disks)
• Spindle to rotate all disks
• Magnetic coating on disk to store bits of data
• Read/write head at the top and bottom of each
  disk
• Actuator to move read/write head over disk
  surface
• Hard drive controller chip directing read/write
  head
• Head (surface) of platter is not the read/write
  head
• Physical organization includes a cylinder
• All tracks that are the same distance from disk
  center

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Figure 8-10 Inside a hard drive case
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Figure 8-11 A hard drive with two platters
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Tracks and Sectors on the Drive

• Tracks on older drives held the same amount of
  data
• Newer drives use zone bit recording
• Tracks near center have smallest number
  sectors/track
• Number of sectors increase as tracks grow larger
• Every sector still has 512 bytes
• Sectors identified with logical block addressing
  (LBA)

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Figure 8-13 Floppy drives and older hard drives
use a constant number of sectors per track
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Figure 8-14 Zone bit recording can have more
sectors per track as the tracks get larger
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Low-Level Formatting

• Two formatting levels
• Low-level mark tracks and sectors
• High-level create boot sector, file system, root
  directory
• Manufacturer currently perform most low-level
  formats
• Using the wrong format program could destroy
  drive
• If necessary, contact manufacturer for format
  program
• Problem track and sector markings fade
• Solution for older drives perform low-level
  format
• Solution for new drive backup data and replace
  drive
• Note zero-fill utilities do not do low-level
  formats

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Calculating Drive Capacity on Older Drives

• Constant number of sectors per track
• The formula was straightforward
• Cylinders x heads x sectors/track x 512
  bytes/sector
• Example 855 cylinders, 7 heads, 17 sectors/track
• 855 x 7 x 17 x 512 bytes/sector 52,093,440
  bytes
• Divide by 1024 twice to convert to 49.68 MB
  capacity

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Drive Capacity for Todays Drives

• The OS reports the capacity of hard drives
• Accessing capacity data using Windows Explorer
• Right-click the drive letter
• Select Properties on the shortcut menu
• Calculating total capacity if drive is fully
  formatted
• Record capacity of each logical drive on hard
  drive
• Add individual capacities to calculate total
  capacity
• Reporting total capacity (regardless of
  formatting)
• Windows 2000/XP use Disk Management
• Windows 9x use Fdisk

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Hard Drive Interface Standards

• Facilitate communication with the computer system
• Several standards exist
• Several ATA standards
• SCSI
• USB
• FireWire (also called 1394)
• Fibre Channel
• The various standards will be covered

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The ATA Interface Standards

• Specify how drives communicate with PC system
• Drive controller interaction with BIOS, chipset,
  OS
• Type of connectors used by the drive
• The motherboard or expansion cards
• Developed by Technical Committee T13
• Published by ANSI
• Selection criteria
• Fastest standard that the motherboard supports
• OS, BIOS, and drive firmware must support
  standard

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Table 8-1 Summary of ATA interface standards for
storage devices
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The ATA Interface Standards (continued)

• Parallel ATA
• Allows two connectors for two 40-pin data cables
• Ribbon cables can accommodate one or two drives
• EIDE (Enhanced Integrated Device Electronics)
• Pertains to how secondary storage device works
• Drive follows AT Attachment Packet Interface
  (ATAPI)
• Four parallel ATA devices can attach with two
  cables
• Serial ATA (SATA) cabling
• Use a serial data path rather than a parallel
  data path
• Types of SATA cabling internal and external

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Figure 8-16 A PCs hard drive subsystem using
parallel ATA
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Figure 8-18 A hard drive subsystem using the new
serial ATA data cable
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The ATA Interface Standards (continued)

• DMA (direct memory access) transfer mode
• 7 modes (0 - 6) bypassing CPU in transfer of data
  
• PIO (Programmed Input/Output) transfer mode
• 5 modes (0 - 4) involving CPU in data transfer
• Independent device timing
• Enables two drives to run at different speed
• ATA/ATAPI-6 (ATA/100) breaks the 137 GB barrier
• Addressable space is 144 petabytes (1.44 x 1017
  PB)
• Must have support of board, BIOS, OS, IDE
  controller

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Figure 8-21 The 137-GB barrier existed because of
the size of the numbers used to address a sector
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The ATA Interface Standards (continued)

• Configuring parallel ATA drives
• Each of two IDE connectors supports an IDE
  channel
• Primary/secondary channels each support two
  devices
• EIDE devices hard drive, DVD, CD and Zip drives
• Devices in each channel configured as
  master/slave
• Designate master/slave jumpers, DIP switches,
  cable
• Configuring serial ATA drives
• One ATA cable supports one drive (no
  master/slave)
• Use an ATA controller card in two circumstances
• IDE connector not functioning or standard not
  supported

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Figure 8-22 A motherboard has two IDE channels
each can support a master and slave drive using a
single EIDE cable
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Figure 8-25 Rear of a serial ATA drive and a
parallel ATA drive
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SCSI Technology

• Small Computer System Interface standards
• For system bus to peripheral device communication
• Support either 7 or 15 devices (depends on
  standard)
• Provide for better performance than ATA standards
• The SCSI subsystem
• SCSI controller types embedded or host adapter
• Host adapter supports internal and external
  devices
• Daisy chain combination of host adapter and
  devices
• Each device on bus assigned SCSI ID (0 - 15)
• A physical device can embed multiple logical
  devices

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Figure 8-28 Using a SCSI bus, a SCSI host adapter
can support internal and external SCSI devices
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SCSI Technology (continued)

• Terminating resistor
• Plugged into last device at the end of the chain
• Reduces electrical noise or interference on the
  cable
• Various SCSI standards
• SCSI are SCSI-1, SCSI-2, and SCSI-3
• Also known as regular SCSI, Fast SCSI, Ultra SCSI
• Serial attached SCSI (SAS) compatible with
  serial ATA
• Ensure all components of subsystem use one
  standard

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Other Interface Standards

• USB (Universal Serial Bus)
• USB 1.1 and USB 2.0 accommodate hard drives
• A USB device connects to a PC via a USB port
• IEEE 1394 (FireWire)
• Uses serial transmission of data
• Device can connect to PC via FireWire external
  port
• Device also attaches to an internal connector
• Fibre Channel
• Rival to SCSI
• Allows up to 126 devices on a single bus

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Figure 8-31 This CrossFire hard drive holds 160GB
and uses a 1394a or USB 2.0 connection
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How to Select a Hard Drive

• Hard drive must match OS and motherboard
• BIOS uses autodetection to prepare the device
• Drive capacity and configuration are selected
• Best possible ATA standard is part of
  configuration
• Selected device may not supported by BIOS
• Troubleshooting tasks (if device is not
  recognized)
• Flash the BIOS
• Replace the controller card
• Replace the motherboard

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Installations Using Legacy BIOS

• Older hard drive standards that may be
  encountered
• CHS (cylinder, head, track) mode for drives lt 528
  MB
• Large (ECHS) mode for drives from 504 MB - 8.4 GB
  
• The 33.8 GB limitation or the 137 GB limitation
• How to install a drive not supported by BIOS
• Let the BIOS see the drive as a smaller drive
• Upgrade the BIOS
• Replace the motherboard
• Use a software interface between BIOS and drive
• Substitute BIOS with ATA connector and firmware

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Steps to Install a Parallel ATA Drive

• Components needed
• The drive itself
• 80-conductor or 40-conductor data cable
• Kit to make drive fit into much larger bay
  (optional)
• Adapter card (if board does not have IDE
  connection)
• Steps for installing parallel ATA drive
• Step 1 Prepare for the installation
• Know your starting point
• Read the documentation
• Plan the drive configuration
• Prepare your work area and take precautions

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Figure 8-32 Plan for the location of drives
within bays
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Steps to Install a Parallel ATA Drive (continued)

• Steps for installing parallel ATA drive
  (continued)
• Step 2 Set the jumpers or DIP switches
• Step 3 Mount the drive in the drive bay
• Remove the bay for the hard drive
• Securely mount the drive in the bay
• Connect the data cables to the drives (can be
  done later)
• Re-insert (and secure) the bay in the case
• Install a power connection to each drive
• Connect the data cable to the IDE connector on
  board
• Attach bay cover and other connections (if
  needed)
• Verify BIOS recognizes device before adding cover
  

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Figure 8-33 A parallel ATA drive most likely will
have diagrams of jumper settings for master and
slave options printed on the drive housing
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Figure 8-41 Connect a power cord to each drive
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Steps to Install a Parallel ATA Drive (continued)

• Steps for installing parallel ATA drive
  (continued)
• Step 4 Use CMOS setup to verify hard drive
  settings
• Step 5 Partition and format the drive
• If installing an OS, boot from Windows setup CD
• If not, use Disk Management utility or Fdisk and
  Format

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Figure 8-45 Standard CMOS setup
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Serial ATA Hard Drive Installations

• No jumpers to set on the drive
• Each serial ATA connector is dedicated to 1 drive
• A simpler installation process
• Install the drive in the bay (like parallel ATA
  drive)
• Connect a power cord to the drive
• Documentation identifies which connector to use
• Example use red connectors (SATA1, SATA2) first
• After checking connections, verify drive is
  recognized

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Figure 8-48 This motherboard has four serial ATA
connectors
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Figure 8-49 American Megatrends, Inc. CMOS setup
screen shows installed drives
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Installing a Hard Drive in a Wide Bay

• Universal bay kit adapts a drive to a wide bay
• Adapter spans distance between drive and bay

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Figure 8-52 Hard drive installed in a wide bay
using a universal bay kit adapter
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Troubleshooting Hard Drives

• Problems occur before and after installation
• Problems may be hardware or software related
• Hardware-related problems will be addressed

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Problems with Hard Drive Installations

• CMOS setup does not reflect new hard drive
• Solution Enable autodetection and reboot system
• Error message Hard drive not found.
• Reseat the data cable and reboot the PC
• Error message No boot device available.
• Insert bootable disk and restart the machine
• Error message 601 appears on the screen
• Connect the power cord to the floppy disk drive
• Error message Hard drive not present
• Restore jumpers to their original state

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Problems with Hard Drive Installations (continued)

• Things to check if CMOS setup does not show drive
• Does your system BIOS recognize large drives?
• Is autodetection correctly configured in CMOS
  setup?
• Are the jumpers on the drive set correctly?
• Are the power cord and data cable connected?

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How to Approach a Hard Drive Problem After the
Installation

• Some post-installation problems
• Corrupted data files
• A corrupted Windows installation
• A hardware issue preventing system from booting
• Preparation steps
• Start with the end user conduct an interview
• Prioritize what you have learned
• Example make data backup your first priority
• Be aware of available resources
• Examples documentation, Internet, Technical
  Support

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Hard Drive Hardware Problems

• Causes of problems present during boot
• Hard drive subsystem
• Partition table
• File system on the drive
• Files required for the OS to boot
• Some things to do if POST reveals problem
• Check the jumper settings on the drive
• Check the cable for frayed edges or other damage
• Try booting from another media e.g. setup CD
• Check manufacturer Web site for diagnostic
  software

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Hard Drive Hardware Problems (continued)

• Bumps are bad
• A scratched surface may cause a hard drive crash
• Data may be recovered, even if drive is
  inaccessible
• Invalid drive or drive specification
• System BIOS cannot read partition table
  information
• Boot from recovery CD and check partition table
• To be covered in later chapters
• Bad sector errors
• Problem due to fading tracks and sectors
• Solution replace the drive

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Troubleshooting Floppy Drives and Disks

• Table 8-4 has two columns
• One identifies errors occurring before and after
  boot
• Another displays troubleshooting tasks

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Table 8-4 Floppy drive and floppy disk errors
that can occur during and after the boot
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Table 8-4 Floppy drive and floppy disk errors
that can occur during and after the boot
(continued)
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Summary

• Current floppy disks are 3 ½ inch, high-density
  disks
• Floppy disk format 80 tracks, each with 8
  sectors
• Hard drive physical organization cylinders,
  tracks, sectors
• Hard drive logical organization boot record,
  file allocation tables, and root directory
• Secondary storage device communicates with system
  using a standard, such as ATA or SCSI

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Summary (continued)

• Parallel ATA (or EIDE) allows connection of up
  to 4 devices
• Serial ATA (SATA) specifies one cable per device
• SCSI group allow up to 7 or 15 physical devices
  and multiple logical devices per physical device
• Other drive interface standards USB, FireWire,
  Fibre Channel
• Newly installed hard drives are usually
  automatically detected by BIOS