data storage devices unit objectives define the common drive interfaces install hard drives, and...

Data storage devices

Unit objectives Define the common drive interfaces Install hard drives, and create

partitions, and file systems Describe optical data storage and use

optical drives and discs Use removable drives Maintain your hard disks Troubleshoot data storage devices

Topic A

Topic A: Drive adapters Topic B: Hard drives Topic C: Optical drives Topic D: Removable storage devices Topic E: Drive maintenance Topic F: Storage device

troubleshooting

Controllers and interfaces

Controller Interface

PC drive interfaces

SCSI IDE IEEE 1394 (FireWire, i.Link) USB 1.1, 2.0 and 3.0

IDE/ATA

Integrated Drive Electronics (IDE) standard

Officially called AT Attachment (ATA) interface

Two categories:– Parallel ATA (PATA) – Serial ATA (SATA)

SATA more popular in consumer PCs PATA prevalent in CompactFlash

ATA standards

ATA — up to 8.3 MBps EIDE, Fast ATA, Fast ATA-2 — proprietary

extensions ATA-2/3 — up to 16.6 MBps ATAPI — tape and CD-ROM support ATA/ATAPI-4 — up to 33 MBps ATA/ATAPI-5 — up to 66 MBps ATA/ATAPI-6 — up to 100 MBps ATA/ATAPI-7 — up to 133 MBps SATA — up to 300 MBps eSATA — 300 MBps

PIO modes

PIO mode 0 = 3.3 MBps PIO mode 1 = 5.2 MBps PIO mode 2 = 8.3 MBps PIO mode 3 = 11.1 MBps PIO mode 4 = 16.7 MBps

DMA modes

Single word 0 = 2.1 MBps Single word 1 = 4.2 MBps Single word 2 = 8.3 MBps Multi word 0 = 4.2 MBps Multi word 1 = 13.3 MBps Multi word 2 = 16.7 MBps

UltraDMA modes

UDMA mode 0 = 16.7 MBps UDMA mode 1 = 25 MBps UDMA mode 2 = 33.3 MBps UDMA mode 3 = 44.4 MBps UDMA mode 4 = 66.7 MBps UDMA mode 5 = 100 MBps UDMA mode 6 = 133 MBps

ATA motherboard connectors

Standard ATA drive cable

High-speed 80-pin ATA drive cable

SATA data cable

Drive capacities

Original Interrupt 13 limit = 504 MB LBA and ECHS — up to 8.4 GB

(through sector translation) Interrupt 13h extensions — up to 128

GB (through BIOS changes) ATA interface limit = up to 137 GB Large LBA — up to 144 petabytes

(144,000,000 GB) (through bits/sector and maximum sectors changes)

Drive identification

ATA supports two drives per controller– One drive is master– Other drive is slave

Older drives– Set jumper or DIP switch– Connect to cable in correct location

Cable select

ATA drive cable

Motherboard

Slave

Master

Primary and secondary channels

Secondary IDE

Primary IDE

SCSI

Standard Bus width BandwidthSCSI 8 bits 5 MBps

Fast SCSI 8 bits 10 MBps

Fast Wide SCSI 16 bits 20 MBps

Ultra SCSI 8 bits 20 MBps

Ultra Wide SCSI 16 bits 40 MBps

Ultra2/LVD 8 bits 40 MBps

Ultra2 Wide 16 bits 80 MBps

Ultra3 16 bits 160 MBps

continued

SCSI, continued

Standard Bus width BandwidthUltra-320 16 bits 320 MBps

Ultra-640 16 bits 640 MBps

Serial-attached SCSI (SAS)

1 bit 80-375 MBps

SCSI device IDs

Each device must have unique ID 0-7 or 0-15 Higher IDs = Higher priority

– Host Bus Adapter would be 7 or 15

Termination

Terminators = resistors Block signal reflections Terminate both ends of the bus Terminator blocks or switches Passive terminators Active terminators

SCSI ID and termination

SCSI ID

Terminationswitch

Differential SCSI

Single Ended (SE) — Signal voltages compared to ground

Differential SCSI– Data lines are paired– Signals are electrical opposites– Signal is read as comparison between

wires in the pair

High-voltage differential (HVD) ± 5V

Low-voltage differential (LVD) ± 3.3V

Other interfaces

ST506/ST412 ESDI USB IEEE 1394 (FireWire, i.Link)

Activity A-1

Distinguishing among drive controllers

Topic B


troubleshooting

Components of magnetic hard drive

Arm Actuator

Head

Platter Spindle

Solid-state drives

Use memory chips (instead of a rotating disk) to read and write data– DDR RAM or flash memory

Less fragile Silent Require constant power source Expensive, but becoming more

common in lightweight notebooks Windows is not optimized for SDDs

Solid-state drive advantages

Faster startup time– Doesn’t need to “spin up”

Higher read speeds – Doesn’t have to move read/write head

Lower power consumption Less heat generated Operates in higher temperatures

– Magnetic drives between 40°F and 130°F– Solid-state up to 160°F

Less risk of failure – Absence of magnetic drive’s mechanical parts

Magnetic drive advantages

Costs less Current capacity is greater than what’s

available with SDDs Higher number of write/erase cycles

than with SDDs Higher write speeds Requires less power than SDDs Powers all the way down when PC is

off

Hard drive geometry

Head crash

Heads contact surface during operation

Heads float ½ of a millionth of an inch above surface

Don’t drop or jolt your PC during operation

Heads parked at shutdown, but damage still possible

Physical installation

1. Shut down the PC and open its case

2. Set drive identification jumpers or switches

3. If SCSI, terminate the drive

4. Install the drive into the PC chassis

5. Connect data and control cables

6. Connect the power cable

Chassis installation

Use any available bay Smaller bays specifically designed for

hard disks Reach of data and power cables Mount horizontally or vertically Sensitive to shock

Data cable connections

Cables are keyed Non-keyed: wire 1 marked with red

stripe Pin 1 socket labeled with number or

triangle Use correct connectors for IDE master

and slave Terminate each end of SCSI bus

Power cable connections

Most use large peripheral power connector

Have triangle corners to insert correctly

SATA uses specialized keyed power connector

Activity B-1

Physically installing a hard drive

Drive preparation steps

Low-level format Partition High-level format

Low-level formatting

Records tracks Divides tracks into sectors Older drives required occasional

reformatting (low-level) Older drives use stepper motor Newer drives use complex sector

arrangements, such as ZBR Low-level formatting not done with OS;

newer drives done at the factory

Partitioning

Divides disk into logical drives Logical drives = volumes Windows XP SP2 supports drives

greater than 137 GB

Partition types

First sector on bootable volume is the master boot record (MBR)

Primary and extended partitions– Primary — Directly accessed by OS– Extended — Contain one or more logical

drives that are accessed by the OS– Up to 4 primary and 1 extended per drive

Partitioning scheme changed for Windows Vista

Partitioning utilities

fdisk fdisk /mbr (rewrites the MBR) Windows Disk Manager

File systems

Logical organization scheme for files– Sector and cluster sizes– How file and folder names are tracked– How file and folder locations are tracked– How files and folders are stored within

clusters

FAT and NTFS

FAT file system

Developed for DOS Supported through current versions of

Windows 16- and 32-bit versions 16-bit version restricted file names

(8.3 rule, no spaces) Slow and limited compared to NTFS Can’t format FAT32 in Windows Vista

Disk Management– Use format command

NTFS file system

Developed for Windows NT Supported in Windows 2000

Professional and all versions of Windows XP, Vista, and 7

32-bit file system 255-character names with spaces Supports larger files and larger

volumes Faster than FAT for large volumes

FAT vs. NTFSFeature FAT16 FAT32 NTFSFile name length 1-8 characters 1-255 characters 1-255 characters

File extensions 0-3 characters 0-255 characters 0-255 characters

Max. file size 2 GB 4 GB Limited only by volume size

Max. volume size

2 GB 32 GB 2 TB

Max. files per volume

Approx. 6500 Unlimited Unlimited

Most often used with

DOS, Windows 3.x and 95

Windows 9x, Me Windows NT, 2000, XP, Vista, 7

Supports file-level security

No No Yes

Supports file compression and encryption

No No Yes

Directory trees

Directory = folder Directories contain files and folders Root directory FAT16 limited root directory to 512

entries

Root directory of C:

Formatting

Creates logical file-storage structures– File allocation table

Destructive process– Sometimes you can recover data

Use format command or Windows Disk Management

Disk Management Healthy Unallocated Formatting Failed Basic Dynamic Not initialized Initializing Online Offline Unreadable Foreign

Activity B-2

Partitioning and formatting a hard drive

Volume mounting

Assign a volume to an empty NTFS folder

Save drive letters

Activity B-3

Mounting a volume

Fault tolerance Recover from hardware or software failure Data is written to more than one drive Recover information from other drives and

parity information Implemented through hardware or software Software:

– Windows Server products– Windows 2000 Professional, Windows XP

Professional, Windows Vista Business, Enterprise, and Ultimate, and Windows 7 Professional, Enterprise, and Ultimate

Hardware — Manually install RAID/SATA drivers during setup

RAID levels

RAID level 0– Striping with no other redundancy

features

RAID level 1– Simple disk mirroring

continued

RAID level 1– Disk duplexing

RAID level 2– Data is striped across all disks in the

array

RAID levels, continued

continued


RAID level 3 – Uses disk striping – Stores error-correcting information– Information written to only one disk in the

array– If disk fails, array cannot rebuild its

contents

continued


RAID level 4– Stripes data and stores error-correcting

information on all drives– Can perform checksum verification

RAID level 5– Combines the best features of RAID– Striping– Error correction– Checksum verification

Choosing a RAID level Boot and system files can be placed on disks

configured for RAID level 1, but not for RAID level 5 RAID level 1 uses two hard disks; RAID level 5

uses 3–32 disks RAID level 1 is more expensive to implement than

RAID level 5 RAID level 5 requires more memory than RAID

level 1 Reading from disk is faster than write access in

both RAID level 1 and RAID level 5 RAID 5 has faster read access than RAID level 1

Striped volume

Reduces the wear on multiple disk drives by equally spreading the load

Increases disk performance compared to other methods of configuring dynamic disk volumes

Mirrored volume

Creates a copy of data on a backup disk One of the most guaranteed forms of

disk fault tolerance Time to write information is doubled If 3 or more volumes are mirrored or

duplexed, RAID 1 is more expensive than other RAID levels

Can’t be striped Requires two dynamic disks Well suited when data is mission-critical

RAID 5

Provides better fault tolerance than a striped volume

Uses disk space more efficiently than a RAID 1 volume

RAID 5 with parity can reconstruct lost data on any disk

Requires minimum of three disks

continued

RAID 5, continued

Performance isn’t as fast as striped volume Reading is as fast Good choice for mission-critical data Parity information based on formula

– 1/n – n = number of physical disks in volume

Software and hardware RAID

Software RAID implements fault tolerance through the computer’s OS

Hardware RAID is implemented through the server hardware and is independent of the OS

Many manufacturers implement hardware RAID on the adapter

Chip on the adapter Battery backup Hardware RAID more expensive

Hardware RAID advantages

Faster read and write response Ability to place boot and system files

on disks with different RAID levels Ability to hot-swap a failed disk More setup options to retrieve

damaged data and to combine different RAID levels within one array

Activity B-4

Exploring fault tolerance

Topic C


troubleshooting

Components of a CD

120 mm plastic discs Layer of reflective metal-alloy foil encased

in transparent plastic Single spiral track 650-700 MB

Recordable CDs

Commercial CDs use “mastering” Commercial CDs contain copy protection Rainbow Books CD-R process called “burning” CD-R can be written once and read many

times Laser colors:

– Cyan (cyan blue)– Phthalocyanine (aqua)– Metalized azo (dark blue)– Formazan (green)

CD-RW can be written multiple times

CD drive components

Tray Spindle

Laser

CD drive components

Control buttons– Start– Stop– Next track– Previous track

Headphone jack Volume control dial Manual eject hole

CD drive speeds

Expressed as #X– # = number of times faster than rate of

CD spin

1X spins 210 to 539 RPM 2X twice as fast as 1X #X accurate up to 12X

DVDs

12 cm diameter, like CDs Thinner than CDs Uses different encoding method Requires a narrower laser beam DVD-R and DVD-RW 1X to 16X Need an MPEG-2 decoder DVD-5 — 4.7 GB capacity 3" mini-disc — 1.5 GB capacity

DVD types

Type Sides Layers Capacity

DVD-5 Single Single 4.7 GB

DVD-9 Single Double 8.5 GB

DVD-10 Double Single 9.4 GB

DVD-14 Double Single/Double

13.3 GB

DVD-18 Double Double 17.1 GB

DVD standards

DVD Forum– DVD-R– DVD-RW– DVD-RAM

DVD+R Alliance – DVD+RW– DVD+R– DVD+ R DL – Not official standards; display the RW

logo

Blu-ray discs

Blu-ray Disc Association Created with a “blue” (violet) 405nm

laser Shorter wave length Larger capacity

– 50 GB dual-layer 12cm– 25 GB single-layer 12cm

continued

Blu-ray, continued

Other types:– Quad-layer (100 GB) discs consisting of

four layers containing 25 GB each– Discs that can hold 200 GB of data on a

single side, using six 33 GB data layers– 400 GB discs containing 16 data layers

of 25 GB each– Hybrid discs that contain both Blu-ray

and DVD layers on the same side of the disc

Might need special hardware or firmware

continued

Blu-ray, continued

Used to store: – High-definition video– Large amounts of data

‘Mini’ 8cm size– For use in consumer electronic equipment – Single-layer discs up to 7.8 GB – Double-layer discs up to 15.6 GB

Types:– BD-R– BD-RE– 12x recording speed

Optical drive installation

Connect – Interface cable– Power cable– Audio cable

Use 5.25" horizontal bay Cables must reach back of optical device

from motherboard Audio cable must reach back of optical

device from sound card Might need to set jumpers or SCSI ID Secure with screws; older bays use rails Verify that door can open freely

Optical drive connections

Internal – IDE– Serial ATA– SCSI

External– IEEE 1394 – USB 2.0 – SCSI– Parallel

Need drivers– Usually detected

by Windows

Drivers

Windows should detect new hardware Windows will try to install correct driver You might be prompted to install from

another source Driver might be supplied on a disc with

the drive Drivers usually available on

manufacturer’s Web site

Activity C-1

Installing an optical drive

Using a CD

Using CD and DVD drives

Read and write CDs in Windows Media Player

Other CD read/write apps:– RealPlayer– Easy CD Creator– Sonic RecordNow!

Play DVDs and Blu-ray discs in Windows Media Player

Must install DVD decoder– Download Windows XP Video Decoder

Checkup utility from microsoft.com

Activity C-2

Using an optical drive

Topic D


troubleshooting

USB flash drives

Popular Small and portable Can have large

capacity: a few MB to many GB

Hot-swappable Make sure the

drive has finished writing

Use the Safely Remove Hardware icon

USB technical specifications

usb.org Good resource: USB Flash Drive

Alliance – usbflashdrive.org

Typical components– Controller with USB interface– Non-volatile memory interface connected

to memory– LED to indicate drive activity

Can have additional features

Flash MP3 player

USB drivers

Provided with:– Windows 2000 Professional– Windows XP– Windows Vista– Windows 7– Mac OS 9, X, and later– Linux kernels 2.4 and later

Security features:– Encryption– Password protection– Fingerprint sensor

Hot-swapping

Can attach or detach without restarting PC

Make sure device has finished writing before you detach it

LED light indicates activity Can also eject device by using

Windows interface

Booting from flash drive

Computer must support booting from flash drives

Flash drive must be bootable Bootable utility typically supplied by

drive manufacturer

Activity D-1

Using a USB flash drive

Floppy disks

Removable data storage Thin, brown, plastic disk Stiff or rigid plastic case

continued

Floppy disks, continued

FDDs – Internal: 34-pin connector– External: USB, IEEE 1394, and eSATA

Data stored via magnetism Read/write heads detect polarization “Door” on disk allows drive access to

recording media Very small capacity by today’s

standards

5.25" floppy disk

Soft flexible outer cover Holds relatively small amount of data

3.5" floppy disk

Hard outer case Metal sliding door Holds more data than 5.25"

Floppy disk storage

Factors:– Number of tracks– Number of sectors in each track

Data is written in concentric circular areas called “tracks”

Floppies have 40 or 80 tracks Tracks are divided into “sectors” Data is stored in sectors

Capacities

Size TracksSectors

per track Density Capacity

5.25" 40 9 Double 360 KB

5.25" 80 15 High 1.2 MB

3.5" 80 9 Double 720 KB

3.5" 80 18 High 1.44 MB

3.5" 80 36 Extra-high 2.88 MB

Write protection

Activity D-2

Examining floppy disks

Floppy controller resources

System resource Typical value

IRQ 6

I/O address range 0x03F0-0x03F7

DMA channel 2

Floppy drive cable

34-pin ribbon cable with 3 or 5 connectors– One connector to drive controller– Other connectors to floppy drives

(up to 2)

5.25" drives use larger, pinch-type connector

3.5" drives use smaller, pin-socket type connector

continued

Floppy drive cable, continued

Cable position determines A: or B: drive letter

Before cable twist is A:

Floppy controller connector

Activity D-3

Installing a floppy drive

Diskette preparation

Format– Records sector structure– Creates file allocation table– Destructive process

Purchase pre-formatted floppies– PC or Macintosh formats

Activity D-4

Formatting a floppy disk (optional)

Tape drives

Used to back up data from hard drive Tapes typically removed to offsite

storage location Low-cost, high-capacity storage

solution Magnetic tapes use burst mode Data written in blocks Tape drives are sequential-access

devices Use compression

Tape formats

QIC DDS DLT and SDLT LTO AIT and SAIT

Tape head cleaning

Accumulate on tape heads– Dirt – Magnetic material– Tape substrate

Get cleaning and maintenance instructions from drive manufacturer

Activity D-5

Comparing types of tape drives

Topic E


troubleshooting

Hard disk maintenance

Remove unnecessary files Scan for errors Defragment disks

Disk Cleanup

Removes following types of files:– Downloaded program files– Temporary Internet files– Offline Web pages in Windows 7 and

operating systems before Windows Vista– Files in the Recycle Bin– Setup log files in Windows 7 and

Windows Vista– Windows temporary files– Thumbnails of picture, video, and other

documents in Windows 7 and Windows Vista

continued

Disk Cleanup, continued

Removes following types of files (continued):– Error reporting files in Windows 7– Optional Windows components that you

aren’t using – Installed programs that you no longer

use– The hibernation file in Windows Vista– Archive files in Windows Vista

On the System Tools menu In Windows Me/XP/Vista/7, you can

remove old system restore points

Activity E-1

Using Disk Cleanup

ScanDisk

Checks hard disk for physical errors and damaged files

Physical disk errors– Moves any data on that area of the disk– Marks the disk so the OS doesn’t store any

more data in the damaged area

Checks for files and folders with invalid file names, dates, or times

Checks for data fragments– Delete the fragment– Fix the fragment– Convert the data to a file

ScanDisk versions

Available in all Microsoft client OSs except Windows NT Workstation

MS-DOS 6.2 has a version of ScanDisk MS-DOS version won’t run in Windows OSs

except for Windows 95 Chkdsk checks NTFS partitions and runs in:

– Windows NT Workstation– Windows 2000 Professional– Windows XP– Windows Vista– Windows 7

Activity E-2

Scanning a disk for errors

Chkdsk

Search FAT and NTFS disks for file system errors

Supported by MS-DOS through Windows XP

Syntax:chkdsk drive:

Optional parameters and switches:chkdsk drive:path\filename ►/f /v /r /x /i /c /l:size

chkntfs used at bootup on NTFS

Activity E-3

Running chkdsk.exe

Disk Defragmenter

Included from Windows 95 on Improves hard disk performance by

reorganizing files on the disk Files can be

– Contiguous– Fragmented

Access from System Tools menu Two modes

– Analyze– Defragment

Disk Defragmenter in Windows XP

Disk selection

Start Defragment

mode

Start Analyze

mode

Runtime graphs

Legend

Disk Defragmenter in Windows 7

Activity E-4

Defragmenting a disk

Defrag.exe

Syntaxdefrag drive:

Optional switchesdefrag drive: /a /f /v

Activity E-5

Running defrag.exe

Topic F


troubleshooting

Recovering deleted files

Deleting files in Windows 1. Move files to Recycle Bin

2. Delete the files permanently

If files are in Recycle Bin, you can select them and click Restore

Third-party utilities might be able to recover deleted files

Third-party diagnostic utilities

Use to:– Diagnose disk troubles– Recover data– Optimize the operations of hard drives

Examples:– Symantec’s Norton SystemWorks– OnTrack® Data Recovery’s Data Advisor – Stellar Data Recovery’s Stellar Phoenix

Troubleshooting hard and floppy drives

Can’t access drive at all Can’t boot from hard drive Space on drive doesn’t match advertised

space Files becoming corrupted System boots from hard drive with a warm

restart, but not from a cold boot Drive letter incorrect Can’t use full space of very large hard drive Drive not auto-detected during boot process

Troubleshooting CD drives

No audio plays from CD CD drive not found Disc can’t be read Buffer underrun Write process fails several minutes after

starting; write process stops at same point on all media you insert

Zip files are corrupted when recorded on a SCSI CD-RW drive

Burned CD-RW disc can’t be read on another computer

Troubleshooting DVD and Blu-ray drives

DVD can’t be played when two displays are being used

UDF-formatted discs can’t be read; you might be able to read some files or none, or the disc might not show up in Explorer

Can’t play DVD movie

Troubleshooting external/removable drives

Device not recognized

Activity F-1

Troubleshooting data storage devices

Unit summary

Defined the common drive interfaces Installed hard drives, and created partitions,

and file systems Described optical data storage and used

optical drives and discs Used removable drives Maintained your hard disks Identified and resolved problems with data

storage devices

data storage devices unit objectives define the common drive interfaces install hard drives, and...

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