storage devices(present)

MOHAMAD ZAWAWI BIN MAH HASAN

MUHMAMAD AZIZIE BIN MEZELAN

• Storage device store information to be recalled and used at a later time

• Storage device consists of: •Storage medium •Storage device

• Three major technology types for information storage:

•Magnetic •Optical or laser •Flash memory •Solid state

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SimNet Concepts Suppor CD: “Storage Concepts”

• Byte

•Kilobyte (KB)

•Megabytes (MB)

•Gigabytes (GB)

• Terabytes (TB)

• Petabyte (PB)

• Exabyte (EB)

= 8 bits

≈ 1 Thousand Bytes

≈ 1 Million Bytes

≈ 1 Billion Bytes

≈ 1 Trillion Bytes

≈ 1 quadrillion Bytes

≈ 1 quintillion Bytes

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3/15/2014 4 p. 5.142 & 5.144 Fig. 5.13 & 5.16

• Magnetic storage devices can be either internal

or external • Internal magnetic hard disks are fixed inside the

system unit

• External magnetic hard disks are portable

3/15/2014 5 SimNet Concepts Support CD: “Removable Disks”

• Internal hard disk is a magnetic storage device with • One or more thin platters that store information

sealed inside the disk drive.

• Read/write heads access the information on surface

• Heads read information while copying it from disk to RAM

• Heads write information when copying it from RAM to disk

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• External hard disks are magnetic

storage media which are portable

storage units that you can connect

to your computer as necessary

• Great for backup storage devices

• Ability to transport your hard disk from one

computer to another

• Port used is USB and eSATA

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• Long term storage system and

application software

• Operating system and application

software are copied from the hard

disk to memory

• Capacity measured in gigabytes

and terabytes (160GB, 250GB,

500GB, 1TB, 2TB, 3TB)

• Use Integrated Drive Electronic (IDE)

and Serial Advanced Technology

Attachment (SATA) port.

• HDD speeds: 5400, 7200, 10000,

12000, 15000 (rpm)

• Like IDE, an I/O bus standard.

• 7 types of cables:

• DB-25 (SCSI-1)

• 50-pin internal ribbon (SCSI-1, SCSI-2, SCSI-3)

• 50-pin Alternative 2 Centronics (SCSI-1)

• 50-pin Alternative 1 high density (SCSI-2)

• 68-pin B-cable high density (SCSI-2)

• 68-pin Alternative 3 (SCSI-3)

• 80-pin Alternative 4 (SCSI-2, SCSI-3)

• A set of disk stations treated as one logical station

• Data are distributed over the stations

• Redundant capacity is used for parity allowing for

data repair

• RAID 0 (disk stripping)

• A stripped set of equal space from at least two drives creates a larger volume.

• RAID 1 (disk mirroring)

• Method of producing fault tolerance by writing all data simultaneously to two separate drives.

• RAID 3 (Bit-Interleaved Parity)

• Improves upon RAID 2

• Disk Controllers can detect whether a sector has been read correctly.

• RAID 4 (block-interleaved parity)

• Stripes data at a block level across several drives, with parity stored on one drive

• Allows recovery from the failure of any of the disks

• RAID 5

• combines benefit both RAID 0 and RAID 1

• A solid-state drive (SSD) is a data storage

device that uses solid-state memory to store

persistent data.

• No Moving Parts.

• Capacity: 32GB, 64GB, 128GB

240GB, 512GB

• Use SATA port.

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Advantage Disadvantage

More Durable Expensive

Better Computer Performance

- Faster Read and Write Speed

- File Fragmentation Has Little

Impact

- Faster Boot

Limited Storage Capacity

Permanent Data Deletion Slower Write Speed on Some

Models

Produce less Noise Relatively Newer Technology

Consume less Power Unreliable Life Expectancy

Generate Little Heat Inability to Recover Lost Data

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• Removable magnetic storage media come in two basic types:

• Traditional floppy disks

• Zip disks

• These storage media are useful for:

• Storing files for backup or security purposes

• Transferring files from one computer to another

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• Floppy Mylar disk

• Housed inside a hard plastic casing

• Thin, flexible plastic disk

• 3.5 inch floppy disks

• also called floppies, diskettes, floppy

disks

• Holds about 1.44 megabytes of

information

• High-capacity disks

• Zip® disk

p. 5.144 Fig. 5.15

• High capacity plastic platter disk

• Called removable hard disks

• Provide a higher storage capacity than Mylar disks

• Example - Zip® disk with capacity of 100MB, 250MB, and 750MB

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DD = double density; HD = high density; ED = extended density

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• CDs

• DVDs

• Both are optical storage

and have three formats:

• Read-only

• Write-once

• Read-and-write

• Read-Only

CD-ROM

DVD-ROM

• One-Time Writable

CD-R

DVD-R

DVD+R

• Fully Read-and-Write

CD-RW

DVD-RW or DVD+RW

or

DVD-RAM

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SimNet Concepts Support CD: “CDs and DVDs”

DVD+R DVD-R

Pronounciation DVD plus R DVD dash R

Backed by DVD+RW alliance (Sony, Yamaha,

Philips, Dell, Microsoft etc.)

DVD Forum (Apple, Pioneer ,

Mitsubishi, Hitachi, Time Warner

etc.)

Drag & Drop Yes, supported. This technology is

code named Mt. Rainier and is a

hardware feature.

No, not supported.

Layers Multiple Single

Size 4 706 074 624 bytes (4488 MB) 4 706 074 624 bytes (4488 MB)

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Different DVD+R and DVD-R

• A Blu-ray Disc (also

called BD) is a high-

density optical disc

format for the storage of

digital information,

including high-definition

video.

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Format Characteristic

DVD-ROM Purchased with data encoded; not able to change

DVD-R, DVD+R Purchased blank; able to be written to once and then

treated like a DVD-ROM

DVD-RW, DVD+RW Purchased blank; able to be written to and erased

multiple times

DVD-RAM Purchased blank; able to be written to and erased just

like a hard or floppy disk

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• have high-capacity storage laminated

inside a small piece of plastic

• do not need a drive with moving parts

to operate

• Capacity: 32,64,128,268,512(MB)

1, 2, 4, 8, 16, 32, 64(GB)

• Memory card need card reader to

connect with computer.

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• CompactFlash (CF)

• xD-Picture Card (xD)

• SmartMedia (SM) Card

• SecureDigital (SD) card and

MultiMediaCards (MMC)

• Memory Stick Media

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