understanding and troubleshooting your pc. chapter 5: understanding, installing, and troubleshooting...

Understanding and Troubleshooting

Your PC

Chapter 5: Understanding, Installing, and Troubleshooting Disk Drives 2

Chapter Objectives

In this chapter, you will learn:– How hard drives work and organize data– How to install a hard drive– How floppy drives work and how to install a floppy

drive– About optical storage technologies and external

and removable storage– How to manage and troubleshoot hard drives


How Hard Drives Work

Hard drives are magnetic storage media that have one, two, or more platters that stack together and spin in unison

Each side of the platter contains two read/write heads The drive fits into a bay inside the computer case,

where it is securely attached Data is written to the disk as bits, where each bit is a

magnetized, rectangular spot on the disk A hard drive requires a hard disk controller, which is

a special-purpose chip that allows the CPU to communicate with a hard drive


How Hard Drives Work


How Data is Organized on a Hard Disk

Physical storage involves how data is written to and organized on the storage media

Logical storage involves how the OS and BIOS organize and view the stored data

Formatting is the process of preparing a disk for reading and writing by defining how files will be organized on the disk– Low-level (physical) formatting– Partitioning– High-level (logical) formatting


Low-Level Formatting

A hard disk must be physically formatted before it can be logically formatted

Low-level formatting of a hard disk is accomplished by writing a pattern of ones and zeroes on the surface of the disk

These ones and zeroes divide the hard drive platter into tracks, sectors, and cylinders

With zone bit recording, the number of sectors per track varies from one track to another


Low-Level Formatting


Partitioning

Partitioning allows you to organize a hard disk into segments and lets you run multiple operating systems on a single computer

Partitioning under Windows 9x– The OS can divide a single physical drive into

more than one logical drive– The partition table at the beginning of the drive

records all these divisions– The first physical sector of the hard drive contains

the Master Boot Record (MBR)


Partitioning


Partitioning

Partitioning Under Windows NT and Later Windows Systems– A drive can have up to four partitions– The active partition is the partition on the hard drive used to

boot the OS– A primary partition has only one logical drive in the partition– An extended partition can have more than one logical drive

• A drive can have only one extended partition

– The system partition contains the OS boot record


Partitioning


High-Level Formatting

High-level formatting places a file system on the disk for each logical drive– A file system allows an operating system to use

the space available on a hard disk to store and retrieve files

The file system also defines the size of the clusters used to store data– A cluster is the minimum unit the operating system

uses to store information


High-Level Formatting

High-level formatting using FAT– Boot record– Bootstrap loader– File Allocation Table

High-level formatting using NTFS– Master file table (MFT)


File Systems


Hard Drive Interfaces

A hard drive interface is the communication channel over which all the data that is read from or written to the hard disk flows

For a hard drive to work in a system, the hard drive interface must be compatible with the hard drive controller, the OS, and the BIOS

With autodetection, the BIOS detects the new drive and automatically selects the correct drive capacity and configuration


IDE/ATA Interface Standards


DMA or PIO Transfer Modes

A hard drive uses one of two methods to transfer data between the hard drive and memory– DMA (direct memory access) transfer mode can

transfer data directly from the drive to memory without involving the CPU

– PIO (programmed input/output) transfer mode involves the CPU and is slower than DMA

Most new systems use DMA


IDE Cabling Methods

40-conductor IDE cable 80-conductor IDE cable Serial ATA (SATA)

cable


Configuring IDE Drives in a System

A motherboard can support up to four IDE devices using parallel ATA cabling– Primary IDE channel, master device– Primary IDE channel, slave device– Secondary IDE channel, master device– Secondary IDE channel, slave device

A cable-select cable has a master connector and a slave connector

The hard drive always should be installed as the master device on the primary IDE channel


Other Interface Standards

SCSI (Small Computer System Interface)

USB (Universal Serial Bus)

FireWire (IEEE 1394)


Preparing to Install a Hard Drive

Make a backup of important data

Read documentation Prepare your work area

and take precautions Plan drive configuration


Setting Jumpers


Mount the Drive in the Bay

Remove the bay for the hard drive and insert the hard drive in the bay

You must be able to mount the drive in the bay securely

Decide whether to connect the data cable to the drive before or after you insert the bay inside the computer case

Place the bay back into position and secure the bay with the screw(s)



Install a power connection to each driveConnect the data cable to the IDE connector

on the motherboardConnect the hard drive light on the front of the

case, if necessaryTest the drive before replacing the computer

case


Use CMOS Setup to Change Hard Drive Settings

When you first boot up after installing a hard drive, go to CMOS setup and verify that the drive has been recognized, the boot order is set correctly, and that settings are correct

Confirm that IDE HDD Auto Detection is enabled

It may be necessary to enter the information about the drive in CMOS manually


Partition and Format a New Drive

Partitioning and formatting a drive while installing Windows

Partitioning and formatting a drive with an installed OS– Disk Management utility

Partitioning and formatting a drive without an OS


Troubleshooting Hard Drive Installations

Check that the formatting utility you used has been run successfully

Verify the CMOS setup has been configured correctly

Your system BIOS must recognize large drivesCheck DIP switch and jumper settingsCheck power cord and data cable connections


How Floppy Drives Work

Floppy drives now are used mainly for troubleshooting a failed boot and as a quick and easy way to transfer small files from one computer to another when a network is not available


How Data is Organized on a Floppy Disk


Optical Storage Technology

This technology uses laser beams to read and write data– CDs and DVDs use optical technology

The surface of an optical disc stores data as pits and lands– Lands are raised areas on the surface– Pits are recessed areas on the surface

The bits are read with a laser beam that distinguishes between a pit and a land by he amount of deflection or scattering that occurs when the light beam hits the surface


Installing a CD-ROM Drive

Follow the same basic steps as for installing a hard drive– IDE interface– SCSI interface– External drive


CD-R and CD-RW

CD-R (CD-recordable) drives allow you to write data to a CD, and can be read by regular CD-ROM drives

No one can edit or overwrite the data on a CD-R disc

A CD-RW (CD-rewritable) drive allows you to overwrite old data on a CD-RW disc with new data


DVD


Troubleshooting Optical Storage Drives and Media


External and Removable Storage


Defrag and Windows Defragmenter

Fragmentation occurs when a single file is placed in several cluster locations that are not directly next to each other

On freshly formatted drives, the OS writes files beginning with cluster 2

After files on the drive have been deleted, the OS writes new files in any available clusters

Since fragmentation is undesirable, you should defragment your hard drive periodically– Defrag command from the command prompt– Disk Defragmenter utility (GUI)


Disk Cleanup

Disk Cleanup is a Windows utility used to delete temporary and other nonessential files on a hard drive


Disk Caching

A disk cache is a temporary storage area in RAM for data being read from or written to a hard drive, and is used to speed up access time to the drive


Enabling Disk Caching


Troubleshooting Hard Drives:An Ounce of Prevention

Be gentle with a hard driveHigh humidity can be dangerous for hard

drivesDo not smoke around your hard driveDo not leave the PC turned off for weeks or

months at a time


Troubleshooting Hard Drives:An Ounce of Prevention

Defragment files and scan the hard drive occasionally

Run antivirus software regularlyMake backups and keep them currentBack up the partition table and boot record


Common Hard Drive Problems

Drive retrieves and saves data slowlyHard drive not spinningHard drive not foundInvalid drive or drive specification


Common Hard Drive Problems

Damaged boot record Damaged FAT or root directory or bad sectors Data and program file corruption


Getting Technical Support

To make calls to technical support more effective, be sure to have the following information ready when you call:– Drive model and description– Manufacturer and model of your computer– Exact wording of error message, if any– Detailed description of the problem– Hardware and software configuration for your

system


Getting Technical Support


Chapter Summary

In this chapter, you learned:– How hard drives work and organize data– How to install a hard drive– How floppy drives work and how to install a floppy

drive– About optical storage technologies and external

and removable storage– How to manage and troubleshoot hard drives

Understanding and Troubleshooting

Your PCChapter 5 Complete

understanding and troubleshooting your pc. chapter 5: understanding, installing, and troubleshooting...

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