Introduction to Storage Devices

Storage Devices

Used to keep data when the power to the computer is turned off.

Medium/mediaLocation where data is stored.

Hard DiskUsually mounted

inside the computer’s system unit.

Can store billions of characters of data.Stated in forms of

bytes: Megabytes,

Gigabytes or Terabytes

Magnetic StorageRecording of data

onto disks or tape by magnetizing particles of an oxide based surface coating.

A fairly permanent type of storage that can be modified.

Used by mainframe or microcomputers

Floppy DiskRound piece of

flexible Mylar plastic covered with a thin layer of magnetic oxide and sealed inside a protective covering.

May be referred to as a “floppy”

3½ disk capacity is 1.44 MB or 1,440,000 bytes

Solid-State StorageFlash memory cards

Widely used in notebook computersUsed to record MP3 music files

Key chain hard drives Key chain flash memory

devicesConnects to a USB port

Optical StorageMeans of recording data as light and dark

spots on CD or DVD.Reading is done through a low-power laser

light.Pits

Dark spotsLands

Lighter, non-spotted surface areas

CD-ROM“CD – Read Only

Memory”Also called CD-R

CD-ReadStorage device that uses

laser technology to read data that is permanently stored on compact disks, cannot be used to write data to a disk.

CD-RW

“CD-Read Write”A storage device that reads data from CD’s and

also can write data to CD’s.Similar to a CD-ROM, but has the ability to write to

CD.

DVDDVD ROM

Digital Video Disk which is read only.DVD-R

Digital Video Disk which can be written to one time. It then becomes read only.

DVD-RWDigital Video Disk which can be rewritten to.

Blu-Ray Technology New standard in storageBlu-Ray

New disks use blue laser light instead of the red laser light used in traditional CD players

Disks may ultimately hold Over 30GB on one-sided disks Over 50GB on two-sided disks

Flash or Jump DrivesExternal storage devices that can be used

like a external hard drive.They have the capability to be saved to,

deleted from, and files can be renamed just like with a normal hard drive.

A hot swappable device is one which can be replaced whilst the server is still in operation.

You should only hot swap components when the component and operating system supports it.

The following components can be hot swapped: RAM, disk drive, power supply, NIC, graphics cards.

Hot swappable components are more expensive. Often only necessary when you need to keep a server operational 24/7.

Hot Swappable

List of Devices for Secondary Storage

Magnetic tape and disksCompact Disk Read-Only Memory (CD-ROM)Write Once Read Many - (WORM)Magneto-optical disksRedundant Array of Inexpensive Disks (RAID)Optical disksDigital Video DisksMemory cardsFlash memoryRemovable storage

ReferencesComputing Essentials 2005M. Guymon. Pleasant Grove High School