Chapter 4 - Secondary Storage!

 
Chapter 4
 Why I should know about this chapter?
o Not right secondary storage will make your computer slow, digital
camera won’t take pictures and your phone won’t be able to run
apps.
 At the end of this lesson, the students should be able to:
o Differentiate between primary and secondary storage.
o Identify the important characteristics of secondary storage including media, capacity,
storage devices and access speed.
o Describe hard-disk platters, tracks, sectors, cylinders and head crashes.
o Compare internal and external hard drives.
o Compare performance enhancements including disk caching, RAID, file compression
and file decompression.
o Define optical storage including compact discs, digital versatile discs and Blu-ray discs.
o Define solid-state storage including solid-state drives, flash memory cards and USB
drives.
o Define cloud storage and cloud storage services.
o Describe mass storage, mass storage devices, enterprise storage systems and storage
are networks.
o Discuss the other types of storage – magnetic stripe card, smart card, RFID tag,
microfilm and microfiche
o Identify/suggest secondary storage for each category of user
Storage •holds data, instructions and
information for future use
Storage medium
•the physical material on which a computer keeps data, instructions, and information
Storage device
•the computer hardware that records and/or retrieves items to and from storage
media
•involves two processes:
Reading is the process of transferring
items from a storage medium into memory
Writing is the process of transferring items

from memory to a storage medium
Secondary Storage
•Provides permanent or nonvolatile storage.

•Items on a storage medium remain intact even when you turn off a
computer or mobile device
 Important characteristics of secondary storage:
o Media – physical material that holds data & programs
o Capacity – how much a particular storage medium can
hold
o Storage devices – hardware that reads data &
programs from storage media
o Access speed – measures amount of time required by
the storage to retrieve data & programs
Capacity
the number of bytes a storage medium
can hold
 A hard disk contains one or more inflexible, circular platters
that use magnetic particles to store data, instructions and
information
 Hard disks use rigid metallic platters that are stacked one
on top of another
 It stores and organizes files using tracks, sectors and
cylinders.
 Hard disks are sensitive instruments.
 The clearance between a hard disk read/write head and the platter is
about 0.000001 inch thick.
 A head crash occurs when a read/write head touches the surface of a
platter – resulting in a loss of data or sometimes loss of the entire disk
 There are two basic types of hard disks :
o Internal hard disk
• Located inside the system unit
• Fast access to retrieve large quantities of information
• Cannot be easily removed from the system unit
o External hard disk
• Slower access
• Usually connected to a USB or Thunderbolt port on the system
unit
• Easily removed
 Performance enhancement techniques:
Technique Description
Disk catching Uses cache and anticipates data needs
RAID Linked, inexpensive hard disk drives

File compression Reduces file size
File decompression Expands compressed files
 Solid-state memory contains no moving parts
 Data and information are stored and retrieved electronically
 Types of flash memory storage:
Solid- USB
Memory
state flash
cards
drives drives
Solid–state devices (SSDs) have no moving parts
 Solid-state drives
o Faster and more durable than hard disks
o Access to slash memory or solid state storage
 Flash memory cards

o Widely used in laptops, smartphones, GPS navigation
systems
 USB Drives (or Flash Drives)

o Connect to USB port
o Capacity of 1 GB to 256 GB
o Portable
Solid-state
drive
•contains its
own
processor to
manage its
storage
Discovering Computers 2014: Chapter 8
Higher storage capacity
Advantages
Faster access times
of SSDs
over Faster transfer rates
traditional Quieter operation
(magnetic) More durable
hard disks: Lighter weight

Less power consumption
Less heat generation
Longer life
Memory card
•a removable flash
memory device
that you insert and
remove from a slot
in a computer,
mobile device, or
card reader/writer

CF (CompactFlash)
Common SDHC (Secure Digital High Capacity)
types of SDXC (Secure Digital Expanded Capacity)
memory miniSD
microSD
cards: microSDHC
microSDXC
xD Picture Card
Memory Stick PRO Duo
M2 (Memory Stick Micro)

USB Flash
Drives
•plug into a
USB port on
a computer
or mobile
device
 Cloud storage is an Internet service that provides storage to
computer or mobile device users
 Supplied by servers that provide cloud storage or online
storage
 Advantages of cloud storage:
Access files from any computer
Store large files instantaneously
Allow others to access their files
View time-critical data and images immediately
Store offsite backups
Provide data center functions

 Disdvantages of cloud storage:
Access Speed
File Security
 Using a cloud storage service makes it easy to upload and share
files with anyone.
Starting Dropbox Dropbox Sharing Dropbox

Step 1 Step 2
 An optical disc consists of a flat, round, portable disc made
of metal, plastic, and lacquer that is written and read by a
laser
 Use reflected light to represent data
o Lands represent 1s and 0s on the disc
o Pits are bumpy areas on the disc that, when light is reflected,
determine the 1s and 0s
o Use tracks and sectors to organize and store files but only
use a single track unlike the hard drive
 Optical discs
commonly store items
in a single track that
spirals from the center
of the disc to the edge
 Track is divided into
evenly sized sectors
A CD-ROM can be A CD-R is an optical
read from but not disc on which
written to users can write
•Single-session disc once, but not erase
A CD-RW is an
erasable
multisession disc
A DVD-ROM is a high-capacity optical disc on which
users can read but not write on or erase
A DVD-R or DVD+R are competing DVD-recordable

WORM formats, on which users can write once but not
erase
DVD-RW, DVD+RW, and DVD+RAM are high-capacity

rewritable DVD formats
 To meet the needs of organizations
requiring large amounts of secondary
storage requirements
 Enterprise storage system
o Safe use of data across an organizational
network
 Devices include:
o File servers
o Networked attached storage (NAS)
o RAID systems
o Organizational cloud storage
 Enterprise hardware allows large organizations to manage
and store data and information using devices intended for
heavy use, maximum efficiency, and maximum availability
RAID
Network attached storage (NAS)
Storage area network (SAN)
Tape
RAID
•duplicates data, instructions, and

information to improve data reliability
Network attached storage (NAS)
• a server that is placed on a network with the sole

purpose of providing storage to users, computers, and
devices attached to the network
Storage area network (SAN)
•a high-speed network with the sole purpose of

providing storage to other attached servers
Tape
•a magnetically coated
ribbon of plastic
capable of storing
large amounts of
data and information
•A tape drive reads
and writes data and
information on a tape
Magnetic stripe card
•contains a magnetic stripe
www.indiamart.com that stores information
Smart card
•stores data on an integrated
www.innoozest.com circuit embedded in the card
RFID tag
• consists of an antenna and a memory
chip that contains the information to
be transmitted via radio waves
www.cardsdc.com
Microfilm and microfiche

• store microscopic images of
documents on a roll or sheet film
 Disaster recovery specialists are responsible for recovering
systems and data after a disaster strokes
 General employer requirements
o Bachelors or associates degree in
computer science or information systems
o Experience in the field and skills in networking, security and DBA
o Communication and skills and be able to handle high-sress situations
 Annual salary of $70 K to $88 K
 Atsome point, hard drives will
no longer be able to keep up
o Looking at ways of increasing
capacity without increasing size
o Currently hard drive maxes out at
128 GB per square inch.
o New technologies may advance
this to 6.25 TG (6,250 GB) per
square inch.
 
1. Compare primary storage and secondary storage, and discuss the most
important characteristics of secondary storage.
2. Discuss hard disks including density, platters, tracks, sectors, cylinders,
head crashes, internal, external, and performance enhancements.
3. Discuss solid-state storage including solid-state drives, flash memory, and
USB drives.
4. Discuss optical disks including pits, lands, CDs, DVDs, Blu-ray, and hi def.
5. Discuss cloud computing and cloud storage.
6. Describe mass storage devices including enterprise storage systems, file
servers, network attached storage, RAID systems, organizational cloud
storage, and storage area network systems.

Chapter 4 - Secondary Storage!

Uploaded by

Copyright:

Available Formats

Chapter 4 - Secondary Storage!

Uploaded by

Document Information

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Chapter 4 - Secondary Storage!

Uploaded by

Copyright:

Available Formats

 

Writing is the process of transferring items

•Provides permanent or nonvolatile storage.

RAID Linked, inexpensive hard disk drives

 Flash memory cards

 USB Drives (or Flash Drives)

traditional Quieter operation

(magnetic) More durable

hard disks: Lighter weight

Discovering Computers 2014: Chapter 8

types of SDXC (Secure Digital Expanded Capacity)

Discovering Computers 2014: Chapter 8

Store large files instantaneously

Allow others to access their files

View time-critical data and images immediately

Store offsite backups

Provide data center functions

Starting Dropbox Dropbox Sharing Dropbox

A DVD-R or DVD+R are competing DVD-recordable

DVD-RW, DVD+RW, and DVD+RAM are high-capacity

•duplicates data, instructions, and

• a server that is placed on a network with the sole

•a high-speed network with the sole purpose of

Microfilm and microfiche

You might also like