Computer Concepts: Chapter 7
Solid State Storage: Flash Memory
- Also know as solid State Storage - offered a combination of features of RAM and ROM. - Like RAM it can be updated. - Like ROM is does not lose information when Computer is turned off. - Little slower than traditional memory but much faster than traditional hard Disks.
Solid-State Storage: USB Drivers or Flash Drivers
- Compact - Conveniently connect directly to a computer's USB port to transfer files. - Popular option to transporting data and information between computers, speciality devices, and the Internet.
Solid-State Storage Devices
- Devices have no moving parts. - Data and Information are stored and retrieved electronically directly from these devices much as they would be from conventional computer memory.
Performance Enhancements: Disk Caching
- Improved Hard-Disk performance by anticipating data needs. - Improves processing by acting as a temporary high speeding area between secondary Storage device and the CPU. - Requires a combination of hardware and software. - Frequently Used Data is automatically identified and read from the hard disk into this. - When needed, the data is the accessed directly from memory.
Performance Enhancement: File Compression and File decompression
- Increase Storage Capacity by reducing the amount of space required to store data and programs. - Not limited to hard Disks. - Frequently Used to compress files on DVDs, CDs, and flash drives. - Helps to speed up transmission of files from one computer system to another. - These programs scan files for ways to reduce the amount of required storage. - One way is to search for repeating patterns. - Repeating patterns are replaced with a token, leaving enough tokens so that the original can be rebuilt or decompressed. - These often shrink files to a quarter of their original size.
2 Types of Hard Disk
- Internal - External
Characteristics of Secondary Storage
- Media - Capacity - Storage Devices - Access Speed
Optical Discs has Three Basic Formats
- Read Only - Write Once - Rewritable
Careers in IT: Disaster Recovery Specialists
- Responsible for recovering systems and data after a disaster strikes an organization. - Create plans to prevent and prepare for such disasters. - A crucial part of that plan is to use storage devices and media in order to ensure that all company data is backed up and, in some cases, stored off-site.
Rewritable (RW for rewritable or RAM for random-Access Memory) Discs
- Similar to write- Once Discs except that the disc surface is not permanently altered when data is recorded. - Popular for storing and sharing audio, video, and large multimedia presentations.
Optical Discs
- hold over 128 GB of data. - Technology: a laser beam alters the surface of a plastic or metallic disc to represent data. - Uses reflected light to represent the 1s and 0s. - The 1s and 0s are represented by flat areas called lands and bumpy areas called pits in the disc surface. - The disc is react an optical disc drive: using a laser that projects a tiny beam of light in these areas - the amount of reflected lights determines whether the area represents a 1 or a 0. - Most widely used: CD, DVD, Blu-ray
External Hard Disk
- use the same technology as internal hard Disks and are used primarily to complement an internal hard disk. - Useful to protect or secure sensitive information. - Backing up the contents of the internal hard disk and providing additional hard-disk capacity. - Provide slower access and are typically connected to a USB or Thunderbolt port in the System Unit and are easily removed. - fixed amount of storage.
Mass Storage: Enterprise Storage System
A strategy to promote efficient and safe use of data across the networks within their organizations. - Some mass Storage Devices that Support this strategy include: File Server, RAID system, Organizational Cloud Storage and Network Attached Storage
Enterprise Storage System: Network Attached Storage (NAS)
A type of file server designed for homes and small businesses. - less expensive, easier to set up, and easier to manage than most file servers. - Does not include powerful management tools and features found in many large scale file servers.
Storage Area Network (SAN) System
An architecture to link remote computer storage devices, such as enterprise Storage systems, to computers such that the devices are as available is locally attached drives. - In this System, the user computer provides the file system for storing data, but this system provides the disk space for the data. - Provide the ability to house data in remote locations and still allow efficient and secure access.
Write- Once (R for recordable) Discs
Can be written on Once. - The disc can be read many times but cannot be written on or erased. - Ideal for creating permanent archives such as CD-R, often used for storing family photos, and DVD-R often used to store home movies.
Secondary Storage Devices
Data and programs can be retained after the computer has been shut off. - This is accomplished by writing files to and reading files from these devices. - Writing: the process of saving information to this device. - Reading: the process of accessing information from this type of storage.
Enterprise Storage System: File Servers
Dedicated computers with very large storage capacities that provide users access to fast storage and retrieval of data.
Solid- State Drives (SSDs)
Designed to be connected inside a personal computer system the same way an internal hard disk would be but contain sold- State memory instead of magnetic disks to store data. - more durable and required less energy - more expensive and lower capacity than hard Disks.
Optical Discs: Read-only (ROM for read only memory) Discs
Discs that cannot be written on or erased by the user. - CDs, DVD movies, and Blu-ray
Hard Disks: Sectors
Each track is divided into invisible wedge-shaped sections.
Characteristics of Secondary Storage: Storage Devices
Hardware that reads data and programs from storage Media. - Most also write to Storage Media.
Enterprise Storage System: Organizational Cloud Storage
High speed Internet connection to a dedicated remote storage facility. - These facilities contain banks of file servers to offer enormous amounts of storage.
Storage: Random-access Memory (RAM)
Holds or stores data and programs that the CPU is presently processing. - Beode data can be orocessed or a program can be run, it has to be in this. - Sometimes referred as primary storage. - Provides only temporary or volatile storage. - Loses all of its contents as soon as the computer is turned off.
Performance Enhancement: Redundant Arrays of Inexpensive Disks (RAID)
Improve performance by expanding external storage, improving access speed, and providing reliable storage.
Enterprise Storage System: RAID Systems
Larger versions of the specialized devices that enhance organizational security by constantly making backup copies of files moving across the organization's networks.
Internal Hard Disk
Located inside the System Unit. - Able to store and retrieve large quantities of information quickly. - Used to store programs and data files.
Characteristics of Secondary Storage: Capacity
Measured how much a particular storage medium can hold.
Characteristics of Secondary Storage: Access Speed
Measures the amount of time required by the storage device to retrieve and programs.
Hard Disks: Head Crash
Occurs when a read-write head makes contact with the hard disk's surface or with particles in its surface. - The Disk surface is scratched and some or all of the data is destroyed.
Secondary Storage
Provides permanent or nonvolatile storage
Density
Refers to how tightly these charges can be packed next to one another on the desk.
Mass storage
Refers to the tremendous amount of Secondary Storage required by large organizations.
Hard Disks: Platters
Rigid metallic ___________ that are stacked one in top of another. - Hard Disks store and organize files using tracks, sectors, and cylinders.
Hard Disks: Tracks
Rings of concentric circles on the platter.
Hard Disks: Cylinder
Runs through each track of a stack of platters. - Are necessary to differentiate files stored in the same track and sector of different platters.
Hard Disk
Save files by altering the magnetic charges of the disk's surface to represent 1s and 0s. - Retrieve data and programs by reading these charges from the magnetic disk. - Characters are represented by positive (+) and negative (-) charges using the ASCII, EBCDIC or Unicode binary codes. - rotate and have read/write heads that move in and out.
Solid-State Secondary: Flash Memory Cards
Small solid-State Storage Devices widely used in portable devices. - Some is the Cards are used within devices such as laptops, smartphones, and GPS navigation systems. - Other Cards provide removable storage.
Mass Storage Devices
Specialized high capacity secondary Storage Devices Designed Do meet organizational demands or data storage.
Cloud Storage: Hardware Upgrades
The cloud service will never run out of disk space and can replace failed hard disks without interruption to the user.
Cloud Storage: Maintenance
The cloud service with take care of disk defragmentation, backups, encryption, and security.
Disadvantages of Cloud Storage: Access Speed
The data transfer rage is dependent upon the speed of your Internet connection, which most likely is not as fast as a user's internal network.
Characteristics of Secondary Storage: Media
The physical material that holds the data and programs.
Disadvantages to Cloud Storage: File Security
Users are dependent upon the cloud service's security procedures, which may not be as effective as your own.
Cloud Storage: File Sharing and Collaboration
Users can share documents, spreadsheets, and files with others from anywhere with an Internet connection.
Cloud Storage: Cloud Computing
Where the Internet acts as a cloud of servers that supply applications to clients as a service rather than a product. - these servers provide cloud storage also known as online storage.
