Storage ch # 7

THE PROCESS OF STORING PERSONAL DATA OR INFORMATION FOR FUTURE USE

IS CALLED STORAGE OF DATA.

STORAGE

Slides By Rana Usman SattarStudent Of BBA(Hons)PMAS Arid Agriculture University RawalpindiGmail: [email protected]: [email protected]

Storage Devices

A storage device is the computer hardware

that records and/or retrieves items to and fromstorage media. Writing is the process of transferringdata, instructions, and information frommemory to a storage medium. Reading is the process of transferring

these items from a storage medium into memory.

STORAGE DEVICES

There are different storage devices.Hard DiskFloppy DiskFlashOptical Disk

STORAGE

Storage Medium

A storage medium also called secondary storage, is the physical material on which a computer keeps data, instructions, and information. Examples of storage media are hard disks, solid state drives, memory cards, USB flash drives, Express Card modules, optical discs, smart cards, magnetic stripe cards, and microfilm Etc.

Storage Medium

Storage Capacity

Capacity is the number of bytes (characters) a storage medium can hold.

For example, a reasonably priced USB flash drive can store up to 4 GB of data (approximately four billion bytes) and a typical hard disk has 320 GB (approximately 320 billion bytes) of storage capacity.

Storage Terms

Kilobyte (KB) 1,024Megabyte (MB) 1,048,576Gigabyte (GB) 1,073,741,824Terabyte (TB) 1,099,511,627,776Petabyte (PB) 1,125,899,906,842,624Exabyte (EB) 1,152,921,504,606,846,976Zettabyte (ZB)

1,180,591,620,717,411,303,424Yottabyte (YB)

1,208,925,819,614,629,174,706,176

Storage Device

HARD DISK A hard disk, also called a

hard disk drive or hard drive, is a storage device that contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information.

HARD DISK

External and Removable Hard Disks

External Hard Disk An external hard

disk, is a separate freestanding hard disk that connects with a cable to a USB port or FireWire port on the system unit or communicates wirelessly.

External Hard Disk

Removable Hard Disk

A removable hard disk is a hard disk thatyou insert and remove from a drive. Sometimesthe drive is built in the system unit. Others areexternal devices that connect with a cable to aUSB port or FireWire port on the system unit.

Removable Disk

Characteristics of a Hard Disk

Characteristics of a hard disk include itscapacity, platters, read/write heads, cylinders,sectors and tracks, revolutions per minute,

transfer rate, and access time.

Storage Devices

RAID A group of two or more

integrated hard disks is called a RAID (redundant array of independent disks). RAID is an ideal storage solution for users who must have the data available when they attempt to access it.

Storage Devices

NAS A network attached storage

(NAS) device is a server connected to a network with the sole purpose of providing storage.

NAS

Hard Disk Controllers

A disk controller consists of a special-purposechip and electronic circuits that control thetransfer of data, instructions, and informationfrom a disk to and from the system bus andother components in the computer.

Types of hard disk interfaces

SATAEIDESCSISAS

Types of hard disk interfaces

SATA SATA (Serial Advanced Technology

Attachment) uses serial signals to transfer data, instructions, and information. The primary advantage of SATA interfaces is their cables are thinner, longer, more flexible, and less susceptible to

interference than cables used by hard disks thatuse parallel signals. SATA interfaces have datatransfer rates of up to 300 MBps and higher.

Types of hard disk interfaces

EIDE EIDE (Enhanced Integrated Drive

Electronics) is a hard disk interface that uses parallel

signals to transfer data, instructions, andinformation. EIDE interfaces can supportup to four hard disks at 137 GB per disk.

Types of hard disk interfaces

SCSI SCSI interfaces, which also use

parallelsignals, can support up to eight or fifteen

peripheral devices. Supported devices include hard disks, optical disc drives, tape drives, printers, scanners, network cards, and much more.

Types of hard disk interfaces

SAS SAS (serial-attached SCSI ) is a

newer type of SCSI that uses serial signals to transfer data,

instructions, and information. Advantages ofSAS over parallel SCSI include thinner, longercables; reduced interference; less expensive;support for many more connected devices atonce; and faster speeds. SAS interfaces havedata transfer rates of 750 MBps and higher.

Flash Memory Storage

Flash memory chips are a type of solid state media, which means they consist entirely of electronic components, such as integrated circuits, and contain no moving parts. The lack of moving parts makes flash memory storage more durable and shock resistant than other types of media such as magnetic

hard disks or optical discs.

Solid State Drives

A solid state drive (SSD) is a storage device

that typically uses flash memory to store data,instructions, and information With available

form factors of 3.5 inches, 2.5 inches, and 1.8 inches, SSDs are used in all types of computers including servers,

desktop computers, and mobile computersand devices such as portable media playersand digital video cameras.

Solid State Drives

Memory Cards

A memory card is a removable flash memory device, usually no bigger than 1.5 inches in height or width, that you insert and remove from a slot in

a computer, mobile device, or card reader/writer.

Memory Cards

Common types of memory cards

MEDIA TYPE STORAGECompact Flash 512 MB to 100

GBSecure Digital 512 MB to 8 GBSDHC 4 to 32 GBMicro SD 1 to 2 GBMicroSDHC 4 to 16 GBX D Picture Card 256 MB to 2 GBMemory Stick PRO Duo 1 to 16 GBMemory Stick Micro (M2) 1 to 16 GB

USB Flash Drives

A USB flash drive, sometimes called a thumb

drive, is a flash memory storage device that plugs

in a USB port on a computer or mobile device.

USB Flash Drives

Express Card Modules

AN Express Card module is a removable device, about 75 mm long and 34 mm wide or L-shaped with a width of 54 mm, that fits in an Express Card slot . Express Card modules can be

used to add memory, storage, communications,multimedia, and security capabilities to a

computer

Express Card Modules

Cloud Storage

Cloud storage is an Internet service that provides storage to computer users .

Types of services offered by cloud storage providers

vary. Some provide storage for specifictypes of files, such as photos or e-mail

messages,whereas others store any type of file.

Cloud Storage

Optical Discs

An optical disc is a type of storage media thatconsists of a flat, round, portable disc madeof metal, plastic, and lacquer that is writtenand read by a laser.Optical discs primarily store software,data, digital photos, movies, and music.Some optical disc formats are read only,meaning users cannot write (save) on themedia. Others are read/write, which allowsusers to save on the disc just as they save ona hard disk.

Optical Discs

With some on one side only. Manufacturers usually place

a silk-screened label on the top layer of thesesingle-sided discs. You insert a single-sided discin the drive with the label side up. Other discsare double-sided. Simply remove the disc fromthe drive, flip it over, and reinsert it in the driveto use the other side of the disc. Double-sideddiscs often have no label; instead, each side of thedisc is identified with small writing around thecenter of the disc. discs, you can read and/or write

Optical Discs

Optical discs store items by using microscopicpits (indentations) and lands (flat areas) that arein the middle layer of the discA high-powered laser light creates the pits.A lower-powered laser light reads items fromthe disc by reflecting light through the bottomof the disc. The reflected light is convertedinto a series of bits the computercan process. A land causes light to reflect,which is read as binary digit 1. Pits absorbthe light; this absence of light is read asbinary digit 0.

Types of Optical Discs

CDSA CD-ROM, or compact disc read-onlymemory, is a type of optical disc that users canread but not write (record) or erase — hence,the name read-only. Manufacturers write thecontents of standard CD-ROMs.A typical CD-ROM holds from 650 MBto 1 GB of data, instructions, and information.

Types of Optical Discs

The speed of a CD-ROM drive determineshow fast it installs programs and accesses the

disc.Original CD-ROM drives were single-speed

driveswith transfer rates of 150 KBps. Manufacturersmeasure all optical disc drives relative to this

originalCD-ROM drive. They use an X to denote theoriginal transfer rate of 150 KBps. For

example,a 48X CD-ROM drive has a data transfer rate of7,200 (48 × 150) KBps, or 7.2 MBps.

Types of Optical Discs

CD-RS and CD-RWSA CD-R (compact disc- recordable) is a

multisession optical disc onwhich users can write, but not erase, their ownitems such as text, graphics, and audio.

Multisessionmeans you can write on part of the disc at onetime and another part at a later time. Each

partof a CD-R, however, can be written on only onetime, and the disc’s contents cannot be erased.

Types of Optical Discs

CD-RS and CD-RWSA CD-RW (compact disc-rewritable) is an

erasablemultisession disc you can write on multipletimes. CD-RW overcomes the major disadvantageof CD-R because it allows users to write andrewrite data, instructions, and information onthe CD-RW disc multiple times — instead ofjust once. Reliability of the disc tends to drop,however, with each successive rewrite.

Types of Optical Discs

To write on a CD-RW disc, you must haveCD-RW software and a CD-RW drive. Thesedrives have write speeds of 52X or more,

rewritespeeds of 32X or more, and read speeds of 52Xor more. Manufacturers state the speeds in thisorder; that is, write speed, rewrite speed, andread speed is stated as 52/32/52. Most CD-RWdrives can read audio CDs, CD-ROMs, CD-Rs,and CD-RWs.

Types of Optical Discs

Archive Discs and Picture CDsMany people use archive discs or Picture CDsto preserve their photos. When you post andshare photos online on a photo sharing community,you can choose to save your collection ofonline photos on an archive disc .Anarchive disc stores photos from an online photocenter in the jpg file format, usually at a maximumresolution of 7200 pixels per photo.

Types of Optical Discs

DVDs and Blu-ray DiscsAlthough the size and shape of a CD and DVDare similar, a DVD stores data, instructions, andinformation in a slightly different manner andthus achieves a higher storage capacity.Widely used DVDs are capable of storing4.7 GB to 17 GB, depending on the storagetechniques used. The first storage techniqueinvolves making the disc denser by packing thepits closer together. The second involves usingtwo layers of pits. For this technique to work,the lower layer of pits is semitransparent so thatthe laser can read through it to the upper layer.This technique doubles the capacity of the disc.

Types of Optical Discs

Blu-rayA newer, more expensive DVD format isBlu-ray, which has a higher capacity and betterquality than standard DVDs, especially forhigh-definition audio and video. A Blu-rayDisc-ROM (BD-ROM) has storage capacitiesof 100 GB, with expectations of exceeding 200GB in the future. Blu-ray Disc (BD) drives andplayers are backward compatible with DVD andCD formats. Some game consoles include a Bluraydrive. Original Blu-ray Disc drives had readspeeds of 4.5 MBps, designated as 1X. Currentread/write speeds of Blu-ray Discs range from 9MBps (2X) to 36 Mbps (8X) in the future.

Other Types of Storage

Magnetic Stripe Cards and Smart CardsA magnetic stripe card is a credit card,entertainment card, bank card, or other similarcard, with a stripe that contains informationidentifying you and the card (shown inFigure 7-1 on page 352). Information stored inthe stripe includes your name, account

number,and the card’s expiration date. A magnetic

stripecard reader reads information stored on the

stripe.

Other Types of Storage

smart cardA smart card, which is similar in size to acredit card or ATM card, stores data on a thinmicroprocessor embedded in the card. Smartcards contain a processor and have input,

process,output, and storage capabilities.

Other Types of Storage

smart card

Other Types of Storage

Enterprise StorageEnterprises use computersand computer networks to manage and storehuge volumes of data and information aboutcustomers, suppliers, and employees.To meet their large-scale needs, enterprisesuse special hardware geared for heavy use, maximumavailability, and maximum efficiency. Oneor more servers on the network have the solepurpose of providing storage to connected users.In an enterprise, some storage systemscan provide more than 185 TB of storagecapacity. Optical disc servers hold hundreds ofoptical discs.