The Complete A+ Guide to PC Repair 5/e Update Chapter 7 Storage Devices.

The Complete A+ Guideto PC Repair 5/e Update

Chapter 7Storage Devices

Chapter 7Storage Devices

© 2012 Pearson Addison-Wesley. All rights reserved.

Chapter 7 ObjectivesChapter 7 Objectives

Install or replace a floppy drive

Define and explain fundamental hard drive terminology

Compare and contrast IDE and SCSI technologies

Install and configure storage devices

Troubleshoot storage device problems

Perform hard drive preventive maintenance

Learn skills for effective communication on the phone


Floppy Drive OverviewFloppy Drive Overview

• The floppy drive allows saving data to disk media. • The floppy drive subsystem consists of three main

parts− the electronic circuits or the controller − the 34-pin ribbon cable− the floppy drive

• The electronic circuits give the floppy drive instructions.− The electronic circuits can be built into the motherboard

or on an adapter.

• The floppy cable connects the floppy drive to the electronic circuits.


Floppy Media and ConstructionFloppy Media and Construction

Disk or Floppy DiskDisk or Floppy Disk

Write-Protect Window Write-Protect Window

Read/Write HeadsRead/Write Heads

A small window in the corner of a floppy disk with a sliding tab to open or close the window.

The media inserted in a floppy drive.

Responsible for placing the data, the 1s and 0s, onto the disk.


Installation of floppy drives is simple after doing the following preliminary homework. Verify that the following are available:

An available drive bay

An available power connection

A motherboard floppy connector or install an additional adapter

A floppy cable4

1

2

3

Floppy Drive Installation or Replacement Floppy Drive Installation or Replacement


Floppy Drive Installation Floppy Drive Installation

Floppy Connector on Motherboard


Floppy Drive ConfigurationFloppy Drive Configuration

Floppy drive cable


Attach cable correctly or destroy devices Attach cable correctly or destroy devices and componentsand components

Attach cable correctly or destroy devices Attach cable correctly or destroy devices and componentsand components

Devices, Devices, adapters, adapters,

controlling controlling circuits can be circuits can be damaged if a damaged if a

cable plugs into cable plugs into the connector the the connector the

wrong way.wrong way.

Devices, Devices, adapters, adapters,

controlling controlling circuits can be circuits can be damaged if a damaged if a

cable plugs into cable plugs into the connector the the connector the

wrong way.wrong way.

Some cables are Some cables are keyed so they keyed so they insert only one insert only one

way into the way into the connector. connector.

Some cables are Some cables are keyed so they keyed so they insert only one insert only one

way into the way into the connector. connector.

Most cables that Most cables that connect to the connect to the

floppy drive are floppy drive are keyed, but the other keyed, but the other

end of the cable end of the cable that connects to the that connects to the controlling circuits controlling circuits is sometimes not is sometimes not

keyed.keyed.

Most cables that Most cables that connect to the connect to the

floppy drive are floppy drive are keyed, but the other keyed, but the other

end of the cable end of the cable that connects to the that connects to the controlling circuits controlling circuits is sometimes not is sometimes not

keyed.keyed.

Tech TipTech TipTech TipTech Tip


Hard Drive OverviewHard Drive Overview

Hard drives are a popular device

for storing data.


Hard Drive ComponentsHard Drive Components

Write and read the 1s and 0s to and from the hard drive surface

When a read/write head touches the hard drive platter

Concentric circle on a hard drive platter.

One corresponding track on all surfaces of a hard drive

Read/Write Heads

Head Crash Track CylinderPlatters Sector

Multiple hard metal surfaces contained in the hard drive

Each track is divided into sectors of 512 bytes


Hard Drive GeometryHard Drive Geometry

Figure 7.3


Hard Drive GeometryHard Drive Geometry

Cylinders versus tracks

Figure 7.5


Hard Drive Interfaces OverviewHard Drive Interfaces Overview

There are two major hard drive interfaces.There are two major hard drive interfaces.

SCSI is most common in network servers and network storage.

SCSI (Small Computer System Interface)

Also known as the ATA (AT Attachment) standard. IDE is most common in

home/office computers.

IDE (Integrated Drive Electronics)


ArchitecturesArchitectures• Both parallel architecture and serial architecture

used with both IDE and SCSI devices• Parallel

– Multiple bits sent simultaneously

– Requires precise timing as transfer rates increase

– Multiple devices on the same bus (2 with PATA)• Serial

– Point-to-point bus where each device has a single connection back to a controller

– One bit at a time– Scales easier– Easier to configure.


IDE TypesIDE Types• PATA (Parallel ATA)

– Internal devices– Slower that SATA– Traditionally when people spoke of IDE, it was PATA

• SATA (Serial ATA)– Internal and

external devices– Faster than

PATA


IDE PATA standardsIDE PATA standards


PATA CablesPATA Cables

• Two types– 40-pin, 40-conductor

• Older• Limited to 18 inches• Prone to crosstalk (data from

one wire interfering with data in another wire)

– 40-pin, 80-conductor• Limited to 18 inches• Required to configure devices as cable select (covered

later)• Required with the higher transfer rate devices


PATA DrivePATA Drive• One 40-pin motherboard PATA connector can

support up to two PATA devices. − Some cables only have two connectors—one that

connects to the motherboard and one that attaches to the PATA device. • If a second device is added, a new cable must be

purchased.


SATA (Serial ATA)SATA (Serial ATA)


A technology used with SATA-PMs that limits the host adapter or port to issuing one command at a time to a single eSATA device.

Command-based

switching

FIS (Frame Info

Structure)

A technology that allows multiple eSATA devices to perform simultaneous operations. It is a faster technology than command-based switching.

SATASATA


eSATAeSATA


SSD (Solid State Drive)SSD (Solid State Drive)


SSDSSD• Data on SSDs is handled differently than with a hard drive

− Write amplification – The minimum amount of storage space affected by a request to write data on a solid state drive.

− Wear leveling - The process of writing and erasing data in different memory blocks of SSDs( solid state drives) to prolong the life of the drive. Methods used:

• Software to track usage and direct write operations• Reserved memory bocks to use when a memory block fails• A combination of the first two techniques

• Two main technologies: SLC and MLC− SLC (single-level memory cell) - A cell that stores one bit in a

memory cell and is more expensive and longer lasting than an MLC. − MLC (multi-level cell) - A cell that stores more than one bit in a

memory cell that is used in a SSD (solid state drive). Contrast with SLC.


SCSI (Small Computer System Interface)SCSI (Small Computer System Interface)

• SCSI – (pronounced scuzzy) an interface standard that connects multiple small devices to the same adapter via a SCSI bus.– SCSI bus - shared by all devices that attach

to one SCSI adapter.– SAS (Serial Attached SCSI) – SAS devices

connect in a point-to-point bus. • Used in the enterprise environment where high

reliability and high mean time between failures is important.


SCSI StandardsSCSI Standards

Table 7.3


Storage Device Configuration OverviewStorage Device Configuration Overview

• Configuration of a hard drive usually includes setting jumpers on the drive, terminating properly, and performing a few software commands.

• Each drive type has a normal configuration method.


PATA Physical InstallationPATA Physical Installation• PATA IDE devices (including hard drives) are simpler to

configure than parallel SCSI device. • The steps for installing a PATA device:

− Keep drive in the protective antistatic container until you are ready to install.

− Use proper anti-static procedures. • Touch the device by the sides • Do not handle the electronics or connectors

− Turn off the computer power and remove the power cord.− Configure jumpers− Physically mount and secure the device. Attach cables.− Configure BIOS if needed.− If a hard drive, prepare the drive for data as described later in

the chapter.


PATA IDE Hard Drive SettingsPATA IDE Hard Drive Settings


Tech TipTech Tip• Determining which cable select connector to use

– When the cable select became a standard with ATA-5, the master connector (the black connector) is at the end of the cable.

– The slave connector (the gray one) is in the middle of the connector

– The blue connector attaches to the motherboard.


Two PATA devices configured as cable selectTwo PATA devices configured as cable select

Figure 7.20


Tech TipTech Tip

• Closed means jumpered or enabled– Storage device documentation varies

in how these are shown. – When documentation shows an option as

closed, jumpered, or enabled, this means to put a jumper over the two pins to configure the option.


PATA InstallationPATA Installation

• Motherboards can have multiple PATA connectors: Primary, Secondary, Tertiary, Quaternary.– The two devices that connect to the

cable the connects to the Primary PATA motherboard connector would be known as Primary master and Primary slave.

– The two devices that connect to the Secondary connector would be known as Secondary master and Secondary slave.


PATA InstallationPATA Installation


SATA Physical InstallationSATA Physical Installation

SATA drives are easy to install

SATA drives do not have SATA drives do not have any master/slave, cable any master/slave, cable select, or termination select, or termination

settings.settings.

Uses a small 7-pin connector Uses a small 7-pin connector that attaches between the that attaches between the

serial ATA controller and the serial ATA controller and the serial ATA drive.serial ATA drive.


SATA Physical InstallationSATA Physical Installation


Installed SATA Hard Drive and AdapterInstalled SATA Hard Drive and Adapter

Figure 7.24


SSD Physical InstallationSSD Physical Installation


Parallel SCSI Configuration OverviewParallel SCSI Configuration Overview


SCSI ID Configuration and TerminationSCSI ID Configuration and Termination

Each device on a SCSI chain, including the SCSI host adapter is assigned a SCSI ID.


SCSI ID ConfigurationSCSI ID Configuration


SCSI TerminationSCSI Termination

• SCSI termination is performed in several different ways– By installing a SIPP

– By installing a jumper

– By setting a switch

– By installing a terminator plug

– By installing a pass-through terminator

– Through software


SCSI CablesSCSI Cables

• Parallel SCSI cabling allows multiple devices to be connected to one SCSI host adapter and share the same SCSI bus.

− Most internal SCSI-1 and SCSI-2 cables are 50-pin ribbon cables. They are also known as an A cable.

− Internal SCSI-3 cables are 68-pin ribbon cables.

• When installing multiple SCSI devices, install one device at a time.

• Always avoid using the cheaper, thinner SCSI cables. They are more susceptible to outside noise.


External SCSI CablesExternal SCSI Cables

Figure 7.29


Installing Internal and External SCSI DevicesInstalling Internal and External SCSI Devices


Tech TipTech Tip

• Use only one technology– If an external drive supports more

than one technology, such as eSATA, FireWire, and USB, attach only one type of cable from the drive to the computer.


Laptop Storage DevicesLaptop Storage Devices

• A laptop normally has a PATA or SATA hard drive installed but could have an SSD instead of or in addition to the hard drive.

• Two methods are used with hard drives installed in portable computers- Proprietary - the hard drive is installed in a

location where it cannot be changed, configured, or moved very easily.

- Removable - the hard drive with a laptop is installed or removed through a 44-pin connector.


System BIOS Configuration for Hard DrivesSystem BIOS Configuration for Hard Drives

• Hard drives are configured through the BIOS Setup program.

- IDE hard drives are normally configured using the Auto-Detect feature included with BIOS. This feature automatically determines the drive type for the system.

- For SCSI hard drive installation the most common CMOS setting for the hard drive type is type 0 or None.


Hard Drive Preparation OverviewHard Drive Preparation Overview

Two steps to hard drive preparation


PartitioningPartitioning

- The first step in preparing a hard drive for use in partitioning.

- Partitioning a hard drive divides the drive so the computer system sees the hard drive as more than one drive.


Partitioning InformationPartitioning Information

• Disk Administrator- A Windows program that allows testing, configuration, and preventive maintenance on hard drives. − Can also use the diskpart command utility

• File system – Defines how data is stored on a drive. Examples of file systems include FAT16, FAT32, exFAT, and NTFS.

• Cluster – The minimum amount of space that one saved file occupies.


Types of PartitionsTypes of Partitions• Primary • Extended

• Further subdivided into logical drives

• Only primary partitions and logical drives get drive letters assigned.

• System Partition (XP and lower) or System Volume (Vista/7) the active hard drive partition that contains the files needed to load the operating system.

• Boot Partition (XP and lower) or Boot Volume (Vista/7) – Partition that contains the bulk of the operating system files.


Types of File SystemsTypes of File Systems

Even though the file system is actually created during the formatting stage of setting up a hard drive, the type of partition you have, determines the maximum size of the partition as well as the cluster size. The cluster size is also dependent on the SIZE of the partition (not the maximum size).


FAT16 Partitions and Cluster SizeFAT16 Partitions and Cluster Size


NTFS Partitions and Cluster SizeNTFS Partitions and Cluster Size

Benefits of NTFS partitions


Tech TipTech Tip

• eSATA drives might already be partitioned– Some eSATA drives are already partitioned

and formatted. – Others have software that runs when the drive

is connected for the first time. – All of them should allow repartitioning and

reformatting.


How Drive Letters Are AssignedHow Drive Letters Are Assigned

The order in which the partitions are assigned drive letters depends on three factors


Hard Drive StructureHard Drive Structure• MBR (Master Boot Record) – part of the partition

table that contains a program that reads the partition table, looks for the primary partitiion marked as active, and goes to tha tpartion to boot the system.


Windows Logical Disk ManagementWindows Logical Disk Management

- In the Windows environment, manage storage devices with a snap-in (an installable module) called Logical Disk Management.

- With Windows 2000 and higher, there are two types of storage- Basic storage- This is what traditionally has been

known as a partition. It is the default method because it is used by all operating systems.

- Dynamic storage- Allows you to create primary partitions, logical drives, and dynamic volumes on removable storage devices. More powerful that basic storage.


Logical Disk Management TermsLogical Disk Management Terms


Logical Disk Management TermsLogical Disk Management Terms


More Logical Disk Management TermsMore Logical Disk Management Terms


necessity

Fault ToleranceFault Tolerance

Allows reading from and writing to multiple hard drives for larger storage areas, better performance, and fault tolerance

RAID (Redundant

Array of Independent,)

Disks

Fault Tolerance

The ability to continue functioning

after a hardware or software failure


Levels of RAIDLevels of RAID


Basic RAID ConceptsBasic RAID Concepts

• The “B’s” are blocks of data. • The “P’s” are where the parity information is

stored for particular blocks of data.


High-Level FormatHigh-Level Format

• The last step in preparing a hard drive for use is high-level formatting.

• A high-level format must be performed on- All primary partitions- Logical drives located within extended

partitions- GPT partitions


High-Level FormatHigh-Level Format

Area of a disk that contains system files.

Previously called DBR or DOS boot record, this section of a disk contains information about the system files (the files used to boot the operating system).

DBR (DOS boot record)

Boot sector

A method of organizing a computer’s file system.

FAT (file allocation table)


Tech TipTech Tip

• How to change the cluster size– If you want to adjust the cluster size on a

partition, you can do it during the high-level format step using the FORMAT command.

– The syntax for the command is FORMAT driveletter: /FS:NTFS /A:clustersize where driveletter: is the letter of the partition and clustersize is of the cluster in the partition.


Troubleshooting DevicesTroubleshooting Devices

Most problems with new drive installation stem from improper configuration of:



The following steps assist with checking possible problems.




Disk Management Status StatesDisk Management Status States


Preventive Maintenance for Hard DrivesPreventive Maintenance for Hard Drives• Keeping the computer system in a clean and cool

operating environment extends the life of a hard drive.

• CHKDSK - A program that locates clusters that are disassociated from the appropriate data files.

• Lost clusters – Sectors on a disk that the file allocation table cannot associate with any file or directory.

• Disk Cleanup – A Windows utility that helps free up hard drive space by emptying the Recycle Bin, removing temporary files, removing temporary Internet files, removing offline files and so on.


Data SecurityData Security

• As preventative maintenance perform a backup of data and the operating system.

• The most important part of a computer is the data within it.

• Traditionally, backups were completed on magnetic tape, but CDs, DVDs, and external drives are viable alternatives today.

• Thin-client environment – systems in which no hard drive is included and data is stored on the network.

This is a new, popular option with many companies.


Tech TipTech Tip

• For critical data, keep backups in a different location– Offsite storage for critical data is important

even for home users in case of disaster such as flooding, fire, or theft.

– A safe deposit box can be used for important data records such as textbooks, income taxes, personal records (insurance policy numbers and financial data).


Hard Drive FragmentationHard Drive Fragmentation

• Over time, as files are added to a hard drive, the files become fragmented, which means that the clusters that make up the file are not adjacent to one another. • In the figure, F1 is one particular file. F2 is a different file.


Hard Drive FragmentationHard Drive Fragmentation

• Fragmentation slows down the hard drive in two ways- The FAT has to keep track of scattered

clusters- The hard drive read/write assembly must

move to different locations on the drive’s surface to access a single file.

• Right-click on a drive and select Properties, Tools tab, use the Defragment Now button.


Disk Caching/Virtual MemoryDisk Caching/Virtual Memory


Tech TipTech Tip

Adding more physical RAM to the motherboard helps with caching


Soft Skills – Phone SkillsSoft Skills – Phone Skills

- During the normal course of business a technician will use the phone to speak with customers, vendors, and technical support staff.

- Phone conversations differ from in-person communication in that when using the phone you only have your words and voice to communicate concepts, professionalism, and technical assistance.

- Some tips for when dealing with someone on the phone include: be patient and speak slowly when giving directions, avoid technical jargon, and speak clearly and loudly.

Questions???Questions???

The Complete A+ Guide to PC Repair 5/e Update Chapter 7 Storage Devices.

Documents

floppy drive overview

floppy drive subsystem

floppy drive instructions

floppy cable

hard drive cables

hard drive overview

hard drive subsystem

hard drive components