Chapter 7
Secondary Storage
Professor Michael J. Losacco
CIS 1150 – Introduction to Computer Information Systems
Overview
Chapter
7
Discuss Secondary Storage Characteristics
Describe Hard Drive Parts
Compare Internal and External Hard Drives
Discuss Performance Enhancements
Define Optical Storage
Define Solid-state Storage
Define Cloud Storage and Cloud Services
Discuss Mass Storage
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Storage
Chapter
7
Primary Storage
Volatile
Temporary
e.g., RAM
Secondary Storage
Nonvolatile
Permanent
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Storage
Chapter
7
Secondary Storage Characteristics
Media
Physical Material that Holds Data and Programs
Devices
Read or Write to or from Media
Access Speed
Time Required to Read Data and Programs
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Storage
Chapter
7
Secondary Storage Characteristics
Capacity
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Storage
Chapter
7
A: — Always Primary Floppy Drive
B: — Secondary Floppy If It Exists
C: — Always Primary Hard Drive
D:, E:, F:, Etc. — Next Available Drive
Hard drive
CD-ROM
DVD
USB
Network
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Hard Disks
Chapter
7
Main Storage for System Unit
Stores Data Using Magnetic Charges
Positive / Negative Charges Represent Bits
Sealed in Airtight Case
Media
Rigid Metallic Platter
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Hard Disks
Chapter
7
Platter
Tracks
Rings of Concentric Circles
Sector
Wedge-shaped Sections
Cylinder
Vertically Passes Through Stack of Platters
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Hard Disks
Chapter
7
Head Crash
Spinning Creates Air Cushion
Floats Read / Write Head Above Platter
Crash
Head Contacts Surface
Clearance = 0.000001”
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Hard Disks
Chapter
7
Internal
OS
Major Applications
External
Connect Via USB
Protect or Secure Sensitive Information
Back Up Internal Hard Disk Contents
Providing Additional Hard Disk Capacity
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Hard Disks
Chapter
7
Performance Enhancements
Disk Caching
Performed During Idle Processing Time
Frequently Used Data Read into RAM Cache
RAID (Redundant Arrays of Independent Disks)
Several Hard Disks Treated as a Large-capacity Drive
Fast Access Speed
High Reliability
File Compression
Reduce Space Required to Store Data and Programs
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Optical Discs
Chapter
7
Laser and Reflected Light Represent Data
Mechanics
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Optical Discs
Chapter
7
CD (Compact Disc)
DVD (Digital Video Disc)
BD (Blu-ray Disc)
Formats
-ROM
-R
-RW, -RE
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Optical Discs
Chapter
7
Storage
CD
700MB
DVD / BD
Two Sides Can be Used
Two Layers of Pits Can be Used
Lower Layer is Semitransparent
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Solid-State Storage
Chapter
7
Solid–state Drives (SSDs)
No Moving Parts, Fast, Durable
Flash Memory Cards
USB Drives (or Flash Drives)
Connect to USB Port
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Cloud Computing
Chapter
7
Internet Service
Provides Storage to Computer Users
Benefits
Access Files From Any Computer
Allow Others to Access Their Files
Store Offsite Backups
Google Apps
Dropbox
Office 365
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Mass Storage Devices
Chapter
7
Enterprise Storage System
File Servers
Networked Attached Storage (NAS)
RAID Systems
Tape Libraries
Organizational Cloud Storage
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Mass Storage Devices
Chapter
7
Storage Area Network (SAN)
Architecture to Link to Remote Storage
User’s Computer Provides File System
SAN Provides Disk Space
Requires
High-speed Network
Special File System
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Careers in IT
Chapter
7
Disaster Recovery Specialist
Recovering Systems and Data After a Disaster
Create Plans to Prevent / Prepare For Disasters
Bachelor's Degree in Computer Science
Skills in Networking, Security, and Database Administration
Good Communication Skills
Able to Handle High-stress Situations
Annual Salary of $70,000 - $103,000
19/19