Chapter 8

A+ Guide to Managing and Maintaining Your PCFifth Edition

Chapter 8

Understanding and Installing Hard Drives

2 A+ Guide to Managing and Maintaining Your PC, Fifth Edition

You Will Learn…

About hard drive technologies

How a computer communicates with hard drive firmware

How a hard drive is logically organized to hold data

How to install a hard drive

How to solve hard drive installation problems


Hard Drive Technologies

Used by hard drive to interface with the system

Used within hard drive to read and write data to the drive


Hard Drive Subsystem


Types of Hard Drive Interfaces

EIDE (Enhanced IDE*)(Enhanced IDE*) interface standards used by most hard drives

Other interface standards

* IDE (Integrated Drive Electronics) (Integrated Drive Electronics)


EIDE Interface Standards Specify data transfer speed more than any

other factor

Considerations when selecting a standard Use fastest standard appropriate for range of the

system and size of the drive

Must be supported by the OS, system BIOS on motherboard, and firmware on the drive

Ultra ATA/100: most popular


EIDE Interface Standards (continued) Modes of transferring data between hard drive

and memory

PIO transfer mode (Programmed Input/Output )

• The original method used to transfer data between the CPU

(through the ATA controller) and an ATA device.

DMA transfer mode (Direct Memory Access)

• Allows certain hardware subsystems within a computer to access system memory for reading and/or writing independently of the CPU.


EIDE Interface Standards (continued)

IDE cabling methods

Parallel ATA (PATA) technology

Serial ATA (SATA) technology

Independent device timing


ANSI Interface Standards


ANSI

Acronym for the AAmerican NNational SStandards IInstitute. Founded in 1918, ANSI is a voluntary organization composed of over 1,300 members (including all the large computer companies) that creates standards for the computer industry.

In addition to programming languages, ANSI sets standards for a wide range of technical areas, from electrical specifications to communications protocols. For example, FDDI, the main set of protocols for sending data over fiber optic cables, is an ANSI standard.


IDE Cabling Methods


IDE Cabling Methods (continued)


IDE Cabling Methods (continued)


Configuring EIDE Drives EIDE standards support two IDE connections,

a primary and a secondary

Each connection can support up to two IDE devices for a total of four devices on a system Primary IDE channel, master device

Primary IDE channel, slave device

Secondary IDE channel, master device

Secondary IDE channel, slave device


Configuring EIDE Drives (continued)


Other Interface Standards

SCSI (small computer system interface)

USB

IEEE 1394

Fibre Channel


How Hard Drives Work


How Hard Drives Work (continued)


Tracks and Sectors on the Drive


Tracks and Sectors on the Drive (continued)CAVCAVShort for constant angular velocity, a technique for accessing data off of rotating disks. With CAV, the disk rotates at a constant speed regardless of what area of the disk is being accessed.

This differs from Constant Linear Velocity (CLV), which rotates the disk faster for inner tracks. Disk drives use CAV, whereas CD-ROMs generally use CLV, though some newer drives use a combination of CAV and CLV.

The advantage of CAV is that it is much simpler to design and produce because the motor doesn't need to change speed. In addition, CLV runs into problems for very high-speed CD-ROMs because there's a brief latency whenever the drive needs to change the rotational speed.


Tracks and Sectors on the Drive (continued)


Tracks and Sectors on the Drive (continued)

A method of recording data on a hard disk drive whereby the sectors per track on the drive are not consistent across the platter.

In general, tracks closest to the center have fewer sectors than tracks toward the outside of the platter where the tracks are larger and can fit more sectors.

Zone Bit RecordingZone Bit Recording


Low-Level Formatting

Occurs at the factory

Process of writing sector and track markings on the disk i.e. creates sectors & tracks

Expected to last for the life of the drive


Considerations When Purchasing a Hard Drive Capacity

Spindle speed

Technology standard

Cache or buffer size

Average seek time

Match drive to motherboard


Communicating with the Hard Drive Controller


Calculating Drive Capacity on Older Drives For drives less than 8.4 GB

Determined by number of heads, tracks, and sectors on the disk, each sector holding 512 bytes of data


Hard Drive Size Limitations

Operating system Maximum size supportedDOS and Windows 9x FAT16 2.1 GB; cannot be used on hard

drives that exceed 8.4 GB

Windows NT/2000/XP FAT16 4 GB

Windows 2000/XP FAT32 32 GB

Windows 9x FAT32 137 GB

Windows 2000/XP with Service Pack

Larger than 137 GB


Methods of Retaining Backward Compatibility CHS (Cylinder, Head, Sector) mode or normal mode

(for drives less than 528 MB)

Large mode or ECHS (Extended CHS) mode (for drives between 504 MB and 8.4 GB)

LBA (Logical Block Addressing) mode (for drives larger than 504 MB)

33.8 GB limitation and 137 GB limitation

Device drivers


Methods of Retaining Backward Compatibility CHS (Cylinder, Head, Sector)

Large mode or ECHS (Extended CHS) mode

LBA (Logical Block Addressing) mode

The drive was accessed by specifying its cylinder, head and sector address. More appropriately, it was referred to as accessing the drive through its "geometry".

A transition change in the way a drive was accessed in order to work around the 504 MB barrier, however, the addressing was still done in terms of cylinder, head and sector numbers and then translated one or more times before actually accessing the drive itself.

It is a means by which a drive is accessed by linearly addressing sector addresses, beginning at sector 1 of head 0, cylinder 0 as LBA 0, and proceeding on in sequence to the last physical sector on the drive, which, for instance, on a standard 540 Meg drive would be LBA 1,065,456. I.e, each sector is assigned a unique "sector number".


How a Hard Drive Is Logically Organized to Hold Data

Steps for preparing a hard drive to hold files

Low-level format (usually done at the factory)

Partitioning the hard drive

High-level format


Hard Drive Partitions and Logical Drives Active partition – It’s the bootable partition. OS installed in this partition.

Only one drive can be set as the active partition on a computer.

Primary partition – The primary partition marked as active contains the OS. Also referred as System Partition.

Extended partition – Can be broken down into smaller drives accessible to the OS. These drives are referred to as logical partitions or logical drives.

Logical partition – Exists in an extended partition.


Partitions and Logical Drives


Hard Drive Partition Table in MBR


Choice of File Systems FAT16

Supported by all Windows systems FAT32 (and VFAT)

Supported by Windows 95 Second Edition, Windows 98, Windows 2000, Windows XP

NTFS Supported by Windows NT, Windows 2000,

Windows XP Each logical drive has its own file system


Size of Logical Drives


When to Partition a Drive

First install a new hard drive

Existing drive is giving errors

Suspect a virus has attacked the drive

Want to wipe a hard drive clean and install a new OS


Installing a Hard Drive1. Set jumpers or DIP switches; physically install

drive; attach power cord and data cable

2. Inform CMOS of new drive

3. If installing an OS on the drive, boot from OS setup CD (and skip next two steps)

4. If drive is not intended to hold an OS, use Fdisk or Disk Management to create partition(s) and divide extended partition into logical drives

5. For second drive, use Format command or Disk Management to high-level format each logical drive


Prepare for Installation

Read documentation

Plan drive configuration

Prepare work area and take precautions


Jumper Settings


Jumper Settings (continued)


Jumper Settings (continued)


Mounting the Drive in the Bay


Mounting the Drive in the Bay (continued)














If the Bay Is Too Large


Use CMOS to Change Hard Drive Settings


Setup for Large-Capacity Hard Drives


Setup for Large-Capacity Hard Drives (continued)


Setup for Large-Capacity Hard Drives (continued)


Using Fdisk to Partition a Drive


Using Fdisk to Partition a Drive (continued)


Using Fdisk to Partition a Drive (continued)


Format Each Logical Drive After using Fdisk, you must reboot the PC

before you format the drive

Commands used to format logical drives C, D, and E:

Format C:/S

Format D:

Format E:


Using Windows to Partition and Format a New Drive

Boot from Window setup CD

Follow on-screen directions to install Windows on new drive

The setup process partitions and formats new drive before it begins Windows installation


Troubleshooting Hard Drive Installations Check CMOS setup to verify that system BIOS

recognizes large drives Verify status of Fdisk Verify that Format C:/S was done Check configuration of CMOS setup Confirm setting of DIP switches or jumpers Check connection of power cord and data cable Refer to Web site of manufacturer for suggestions


Summary Introduction to hard drive technology How a hard drive is logically organized Physical characteristics of a hard drive How the OS and system BIOS communicate

with the hard drive How to install a hard drive Troubleshooting hard drive installation

problems

Documents

Chapter 8