Introduction to Storage Devices

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Introduction to Storage Devices
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Storage Devices

• Used to keep data when the power to the computer
  is turned off.
• Medium/media
• Location where data is stored.

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Hard Disk

• Usually mounted inside the computers system
  unit.
• Can store billions of characters of data.
• Stated in forms of bytes
• Megabytes, Gigabytes or Terabytes

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Magnetic Storage

• Recording 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

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Floppy Disk

• Round 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

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Solid-State Storage

• Flash memory cards
• Widely used in notebook computers
• Used to record MP3 music files
• Key chain hard drives
• Key chain flash memory
  devices
• Connects to a USB port

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Optical Storage

• Means of recording data as light and dark spots
  on CD or DVD.
• Reading is done through a low-power laser light.
• Pits
• Dark spots
• Lands
• Lighter, non-spotted surface areas

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CD-ROM

• CD Read Only Memory
• Also called CD-R
• CD-Read
• Storage device that uses laser technology to read
  data that is permanently stored on compact disks,
  cannot be used to write data to a disk.

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CD-RW

• CD-Read Write
• A storage device that reads data from CDs and
  also can write data to CDs.
• Similar to a CD-ROM, but has the ability to write
  to CD.

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DVD

• DVD 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-RW
• Digital Video Disk which can be rewritten to.

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Blu-Ray Technology

• New standard in storage
• Blu-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

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Flash or Jump Drives

• External 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.

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Hot Swappable

• 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.

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List of Devices for Secondary Storage

• Magnetic tape and disks
• Compact Disk Read-Only Memory (CD-ROM)
• Write Once Read Many - (WORM)
• Magneto-optical disks
• Redundant Array of Inexpensive Disks (RAID)
• Optical disks
• Digital Video Disks
• Memory cards
• Flash memory
• Removable storage

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References

• Computing Essentials 2005
• M. Guymon. Pleasant Grove High School