Chapter 08: Secondary Storage McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved mputing Essentials 2012: Making IT Work for You Competencies (Page of 2) • Distinguish between primary and secondary storage • Discuss the important characteristics of secondary storage, including media, capacity, storage devices, and access speed • Describe hard disk platters, tracks, sectors, and head crashes • Compare internal and external hard drives • Discuss performance enhancements including disk caching, RAIDs, file compression, and file decompression McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-2 mputing Essentials 2012: Making IT Work for You Competencies 2) (Page of • Define optical storage including compact, digital versatile, and high-definition discs • Define solid-state storage, including solidstate drives, flash memory, and USB drives • Define cloud storage and cloud storage services • Discuss mass storage devices, enterprise storage systems, and storage area networks McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-3 mputing Essentials 2012: Making IT Work for You Introduction • Data storage has expanded from text and numeric files to include digital music files, photographic files, video files, and much more • These new types of files require secondary storage devices with much greater capacity • In this chapter, you learn about the many types of secondary storage devices including their capabilities and limitations McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-4 mputing Essentials 2012: Making IT Work for You Storage • Primary storage – Volatile storage – Temporary storage – Random Access Memory (RAM) McGraw-Hill • Secondary storage – Nonvolatile storage – Permanent storage • Secondary storage characteristics – – – – Media Capacity Storage devices Access speed Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-5 mputing Essentials 2012: Making IT Work for You Secondary Storage Devices • Provides permanent or nonvolatile storage • Data and programs can be retained after the computer has been shut off • Most desktop microcomputer systems have both hard and optical disk drives McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-6 mputing Essentials 2012: Making IT Work for You Hard Disks • Use rigid, metallic platters for storage • Files organized using tracks, sectors, and cylinders • Large capacity (terabytes) • Sensitive instruments • Two types of hard disks: – Internal Hard Disk – External Hard Disks • Performance enhancements McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-7 mputing Essentials 2012: Making IT Work for You Materials that Cause a Head Crash • A head crash is a disaster for a hard disk, not to mention the data stored on the disk McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-8 mputing Essentials 2012: Making IT Work for You Internal Hard Disk • Located inside system unit and often designated as the C: drive • Used to store programs and data files • Advantages over removable media – Capacity – Access speed McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-9 mputing Essentials 2012: Making IT Work for You External Hard Disks • Removable hard disks • Used to complement internal hard disk with an unlimited amount of additional storage • Capacities extend into the terabytes (TBs) McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-10 mputing Essentials 2012: Making IT Work for You Performance Enhancements • Disk caching to improve hard disk performance • Redundant arrays of inexpensive disks (RAID) to expand storage and to improve access speed • File compression and decompression to increase capacity McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-11 mputing Essentials 2012: Making IT Work for You Optical Disks • Hold over 100 gigabytes (GB) of data • Attributes – – Lands Pits • Three types – – – McGraw-Hill Compact Disc (CD) Digital Versatile Disc (DVD) Blu-Ray (Hi-Def) Disc Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-12 mputing Essentials 2012: Making IT Work for You Compact Disc (CDs) • Optical format • Capacity of 650 MB to GB • Rotation speeds vary • Three basic types – – – McGraw-Hill Read only (CD-ROM) Write once (CD-R) Rewriteable (CD-RW) Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-13 mputing Essentials 2012: Making IT Work for You Digital Versatile Discs (DVDs) • Like CDs, but newer format called digital versatile disc or digital video disc (DVD) • Capacity of 4.7 GB to 17 GB • Three basic types – Read only (DVD-ROM) – Write once (DVD+R and DVD-R) – Rewriteable (DVD+RW, DVD-RW, and DVD-RAM) McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-14 mputing Essentials 2012: Making IT Work for You Blu-ray Disc (BDs) • Next generation optical disc for recording high-definition (hi def) video • Capacity of 25 GB to 100 GB • Blu-ray optical drives are usually capable of reading standard DVDs and CDs in addition to Bluray discs McGraw-Hill Return Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-15 mputing Essentials 2012: Making IT Work for You Solid-State Storage • Solid–state drives (SSDs) – Faster and more durable • Flash memory cards – Widely used in computers, cameras, and portable devices such as mobile phones • USB Drives (or Flash Drives) – Compact and easily transported – Capacity of GB to 256 GB McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-16 mputing Essentials 2012: Making IT Work for You Making IT Work for You Flash Camcorders, YouTube, and MySpace • Flash-based camcorders have made creating digital video simpler and more affordable • Easily upload your creations to photoand video-sharing Web sites on the Internet McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-17 mputing Essentials 2012: Making IT Work for You Cloud Storage • Cloud computing is where the Internet acts as a “cloud” of servers – Applications provided as a service rather than a product (for example, cloud or online storage) • Cloud storage services make it easy to upload and share files with anyone McGraw-Hill Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-18 mputing Essentials 2012: Making IT Work for You Mass Storage Devices • Organizations require tremendous amounts of secondary storage called mass storage • Enterprise storage systems ensure data security using specialized strategies and devices, such as – – – – – – McGraw-Hill File servers Networked attached storage (NAS) RAID systems Tape libraries Organizational cloud storage Storage Area Network (SAN) Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-19 mputing Essentials 2012: Making IT Work for You McGraw-Hill Enterprise Storage Systems Copyright © 2012 The McGraw-Hill Companies, Inc All rights reserved 8-20