A+ Certification Guide

Chapter 12

Storage Devices

Chapter 12Objectives

� Drive Interface Types

� Hard Disk Drives

� SSD / Flash Drives

� Identify External Removable Storage

� RAID

� Optical Drives

� Floppy Drives

� Tape Drives

� Troubleshooting Storage

Storage Principles

� Data storage uses a file table:

– An index to the filenames

� Data storage can be

– Internal

– Externally attached

– Accessed remotely

� Storage devices can become unreliable:

– All mechanical devices eventually fail.

– Redundant data storage is essential.

External/Internal Drive InterfacesInterface Location

Interface Speeds

Drive Types Supported

eSATA

External

1.5Gbps

3Gbps

6Gbps

Hard disk drives

IEEE 1394a (FireWire 400)

400MbpsHard disk drives, optical drives, tape backups

IEEE 1394b (FireWire 800)

800MbpsHard disk drives, optical drives, tape backups

Fast Ethernet External (Network)

100Mbps

Hard disk drives for network accessGigabit Ethernet 1000Mbps

USB 2.0

External

480MbpsHard disk drives, flash memory, card readers, floppy drives, optical drives

USB 3.0 5Gbps Hard disk drives, SSD, flash memory, card readers, floppy drives, optical drives

SATA1*

Internal

1.5GbpsHard disk drives, optical (DVD, BD media) drives, RAID arrays, SSD

Can be converted to eSATA via header cable

SATA2* 3.0GbpsHard drives, optical (DVD, BD media) drives, RAID arrays,

SSD, Can be converted to eSATA via header cable

SATA3* 6.0GbpsHard drives, RAID arrays, SSD

Backwards compatible with SATA1, SATA2

Data Storage Connectors

PATA and SATA Drives

� PATA—Parallel Advanced Technology Attachment:

– Derived from ATAPI/IDE (Integrated Drive Electronics).

– Data bits are sent in parallel using 40-pin ribbon wire.

• Drive jumper positions can also determine role.

– Color of ribbon wire connector determines drive role.

• Roles are Primary/Master and Secondary/Slave.

• 80-wire ribbons offer “cable select” option for role.

– Drive uses a five-pin Molex power connector.

� SATA—Serial Advanced Technology Attachment:

– L-shaped power cable.

– Data cable has only seven wires (much easier on airflow).

– Use one drive per adapter port.

• No jumper blocks needed.

Hard Disk Power and Data Cables

Hard Disk Drive (HDD)

� Used to store the operating system.

� Made of circular metal oxide-coated platters:

– Coating can be magnetically charged to create small areas called fluxes.

• Direction of the flux makes it a binary 1 or 0.

� Platters divided into tracks (concentric circles).

� Each circle is divided into sectors (like pieces of a pie).

� Each sector hold 512 bytes of data (4,096 fluxes):

– Sectors x tracks x 512 = drive capacity

� Two types of drives in current use:

– PATA—Also called ATA/IDE – on older motherboards

– SATA—Currently most popular

Characteristics of Hard Drives

� Spin Rate

– Higher spin rate = faster data access

� Buffer Size

– Memory cache for recently accessed files

– Ranges from 8MB–64MB

� Hybrid features

– Solid State memory combined with normal platter

based storage

– SLC memory is faster

Hard Drive Installation

� BIOS configuration (after physical installation)

– PATA:

• Can usually default to auto-detect.

• If not hard drive parameters must be calculated and configured in BIOS under Hard Drive (HDD) settings.

– SATA:

• If necessary, enable the SATA host adapter.

– Shut down after saving BIOS settings.

• Connect SATA drive and restart system.

– Enter BIOS and verify SATA drive detection.

� At this point, the drive can be formatted for data storage/OS installation.

SATA Installation

Enabling SATA in BIOS

PATA Drive Performance

� Select correct PIO or DMA transfer mode in BIOS.

� Select the correct block mode in the BIOS.

� Install bus mastering Windows drivers.

– Bypasses the CPU for data transfers to RAM.

� Enable DMA/UDMA mode in Windows.

– Verify that drive, cable, and adapter are compatible.

� Adjust disk cache software settings.

� Most of these performance enhancements are done automatically by either the BIOS or the OS.

Removable Storage

� Types:

– USB 1.0/ 2.0/3.0 (flash memory and external hard disks)

– Parallel port

– SCSI

– ATAPI

– IEEE 1394a–FireWire (some external hard disks)

� Tape Drives:

– Native (uncompressed)

– Compressed

– Usually use SCSI interfaces

– Often come with automated backup software

� Flash Memory:

– Many types

Flash Memory Formats

Flash Memory Reader Slots

Figure 12-19

12fig19

SSD Memory Drive USB Adapter

Redundant Array of Independent Disks (RAID)

RAID types of most interest:

� RAID 0—Two drives with striping.

– No redundancy; only good for performance.

� RAID 1—Two mirrored/duplexed drives.

– Data redundancy; small decrease in performance.

� RAID 5—Minimum of three drives with striping.

– Data redundancy; increase in performance.

– Equivalent of one drive required for redundancy calculations (parity function).

� RAID 10 (or 0+1)—Needs four drives.

– Better redundancy than RAID 0; better performance than RAID 1.

RAID Configuration

� Must have a motherboard that supports one of the RAID types.

� When changing to a RAID system, existing data will likely be lost. Back it up.

� Sizing for RAID 5:

– For maximum benefit, all drives should be of similar size.

• The smallest drive determines the capacity.

• Capacity equals smallest drive x number of drives minus the capacity of the smallest drive (for parity).

– Parity is the math calculation performed on the drives that allows a single drive to fail and still recover the data.

– Example, RAID 5, 3 drives: 40GB, 60GB, 60GB drives:

» Storage capacity is (3 x 40) – 40 = 80 GB

– A RAID drive is treated as a single drive after it is configured.

CD/DVD Optical Drive

� Optical Drive Types:

– Compact Disc (capacity 650MB–870MB)

• CD–ROM

• CD–Recordable (CD-R) (one-time recordable)

• CD–Rewritable (CD-RW)

• Mini Disc (capacity 185MB–210 MB)

– Digital Video Disc (capacity 4.7GB–17GB)

• DVD–ROM

• DVD Rewritable (DVD-RW)

• DVD Rewritable +R/RW

• DVD Rewritable–R/RW

• DVD-RAM

– Blu-ray – 25-50GB capacity

� Data is created by laser light etching the surface to create indentations/pits.

– Lands are the space between pits.

– A binary “1” is a change from a pit to a land or vice versa.

Optical Media Installation/Configuration

� Internal CD/DVD:– CD is usually PATA or ATAPI (same thing).

– DVD can be PATA or SATA interface.

� External CD/DVD:– Typically use USB 2.0.

� Installation:– Plug ‘n’ play is normally sufficient for basic operation.

– Manufacturer-based drivers optimize capability.

� Issues:– Disc compatibility:

• CD-R versus CD-RW versus CD+R/RW versus CD–R/RW.

• DVD RW versus DVD-RAM, and so forth.

– Driver limitations—May prevent playback on any machine other than the one it was recorded on.

Choosing File Systems for CD/DVD

� Live File System:

– Drag and drop file recording.

– File greater than 2GB supported.

– Cannot be used on many stock consumer CD/DVD

players found in homes and autos.

� Mastered:

– Can be read by most consumer media systems.

– Limit of 2GB of files can be recorded.

Floppy Disk Drives

Yes, they are still in use.

� 1.44Mb capacity most common.

� Connects to motherboard with 34-pin cable.

– Has a twist in the cable.

– Red stripe on side with pin 1.

� 4-wire miniature jack.

� Write-enabled slider—for protecting data from

accidental erasure.

� Use IRQ 6/address 3F0–3F7h.

Have largely been replaced by USB memory.

Remote Storage

� Network Attached Storage:

– Independent appliance connected to network

– Managed remotely using HTML web page

– Used in small to medium-sized businesses and

residences

� Storage Area Networks:

– High-speed storage system

– Redundant arrays (RAID 3, 4, 5, 10)

– Fiber-optic connections

– Used in industrial high-end data systems

Troubleshooting Storage

Sources of problems:

� Power cable

� Data cable

– Incompatible cable connectors

– Jumpers not set for Primary/Master or Secondary/Slave

� BIOS configuration problems

� Drive defects

– Drive heads misaligned

– Mechanisms jammed

– Drive motor failure

Trouble Symptoms

� Read/write failure

– Look for physical damage, overheating.

� Slow performance

– Check cable type, BIOS configuration.

� Loud clicking noise indicates drive imminent failure

� Failure to boot –Check BIOS settings, connections.

� Drive not recognized: Check BIOS settings, connections.

� OS not found: Check for MBR, boot sequence on multi OS.

� RAID not found: Check BIOS and data cables.

� RAID stops working: Check for drive failure.

Troubleshooting CD/DVD Devices

� Can’t write to media? Check for

– Incompatible media:

• CD-R versus CD-RW versus CD +R/RW, and so on.

– Closed media (indicates not enough space):

• Enable multiple sessions.

– Packet-writing problems:

• Rewritable media can be particular about format.

– DVDs are especially difficult across platforms.

» PC versus Consumer DVD playback systems.

– Media problems:

• Damage from sunlight, heat sources, or scratches to surface.

– Incorrect insertion of media.

Troubleshooting CD/DVD Devices

� Types of Problems:

– The program doesn't detect the drive.

– The program doesn't list the drive as a target drive for writing files.

– When installing the program, it indicates that no compatible CD or DVD drives were found.

– The program detects the drive but displays an error message when trying to write files to the drive.

� Quick Solutions:

– Double-check for correctly installed cable connections.

– Update drivers/software support files from the drive manufacturer.

– Update third-party software; verify that the drive is supported.

Disk Drive Tools

� Windows

– Chkdsk

– Format/Fdisk

� Manufacturer provided Hard Disk Diagnostics

– Western Digital

– Hitachi

� Data Recovery/Third-Party tools

– SpinRite

– Partition Magic

– Linux Live

– Knoppix Linux Live

What Have You Learned?

– What is an advantage of a SATA drive?

– What is the standard sector size on a hard disk

drive?

– What types of connectors can be used with an

external hard disk?

– What problems can be expected from a DVD

recorded on the PC when playing back on the DVD

connected to your television?

– Why might the installation of Linux in a dual-boot

configuration cause problems for the Windows OS?

Chapter 12Summary

� Drive Interface Types

� Hard Disk Drives

� SSD / Flash Drives

� Identify External Removable Storage.

� RAID

� Optical Drives

� Floppy Drives

� Tape Drives

� Troubleshooting Storage.

Next Lesson: Chapter 13