Chapter 3 - CC1 (Part 1 and 2).pptx

15th Edition Understanding Computers Today and Tomorrow Comprehensive Chapter 3 Storage Deborah Morley Charles S....

15th Edition Understanding Computers Today and Tomorrow Comprehensive Chapter 3 Storage Deborah Morley Charles S. Copyright 2015 Cengage Learning  Learning Objectives 1. Name several general characteristics of storage systems. 2. Describe the two most common types of hard drives and what they are used for today. 3. Discuss the various types of optical discs available today and how they differ from each other. 4. Identify some flash memory storage devices and media and explain how they are used today. 5. List at least three other types of storage systems. 6. Summarize Understanding Edition the Computers: Today storage and Tomorrow, 15th alternatives for a typical 2  Overview This chapter covers: – The characteristics common among all storage systems – The primary storage for most personal computers—the hard drive – How optical discs work and the various types that are available today – Flash memory storage systems – Network and cloud storage, smart cards, holographic storage, and storage systems used with large computer systems Edition – Storage alternatives for a typical personal Understanding Computers: Today and Tomorrow, 15th 3  Storage System Characteristics Storage Media and Storage Devices – Medium Hardware where data is stored DVD disc, flash memory card, etc. – Device DVD drive, flash memory card reader, etc. Medium is inserted into device to be used – Can be internal, external, or remote – Storage devices are typically identified by letter Understanding Computers: Today and Tomorrow, 15th 4 Edition  Storage System Characteristics Understanding Computers: Today and Tomorrow, 15th 5 Edition  Storage System Characteristics Volatility – Storage media are nonvolatile Random vs. Sequential Access – Random access (direct access) allows data to be retrieved from any location on the storage medium – Virtually all storage devices use random access – Sequential access means retrieval of data can occur only in the order in which it was physically stored on the storage medium Magnetic tape drive Understanding Computers: Today and Tomorrow, 15th 6 Edition  Storage System Characteristics Logical vs. Physical Representation – File Anything stored on a storage medium, such as a program, document, digital image, or song – Filename Name given to a file by the user – Folder Named place on a storage medium into which files can be stored Understanding Computers: Today and Tomorrow, 15th 7 Edition  Storage System Characteristics Understanding Computers: Today and Tomorrow, 15th 8 Edition  Storage System Characteristics – Logical file representation Individuals view a document stored as one complete unit in a particular folder on a particular drive – Physical file representation Computers access a particular document stored on a storage medium using its physical location or locations Types of Storage Technology Used Magnetic (conventional hard drives) Optical (optical discs) Electrons (flash memory media) Understanding Computers: Today and Tomorrow, 15th 9 Edition  Hard Drives Hard Drive – Used to store most programs and data – Can be internal or external – Can be encrypted Magnetic Hard Drives – One or more Edition permanently Understanding sealed Computers: Today and Tomorrow, 15th 10  Hard Drives Understanding Computers: Today and Tomorrow, 15th 11 Edition  Hard Drives Hard disks are divided into: – Tracks Concentric path on disk where data is recorded – Sectors A small piece of the track – Clusters One or more sectors; smallest addressable area of a disk – Cylinders Collection of tracks located in the same location on a set of hard disk surfaces Understanding Computers: Today and Tomorrow, 15th 12 Edition  Hard Drives Understanding Computers: Today and Tomorrow, 15th 13 Edition  How It Works Box More Storage for Your Tablet – Media tablets often have 64 GB of storage – To extend storage, can transfer content to and from PCs – Easier is to use a wireless hard drive – Need the appropriate Understanding app Computers: Today and Tomorrow, 15th 14 Edition  Hard Drives Solid State Drives (SSDs) – Use flash memory technology – Use less power and have no moving parts – Particularly appropriate for portable computers and mobile devices Understanding Computers: Today and Tomorrow, 15th 15 Edition  Inside the Industry Box Data Recovery Experts – Can recover data from damaged storage devices – Can be used when devices are physically damaged or just stop working – Back up to prevent data loss Understanding Computers: Today and Tomorrow, 15th 16 Edition  Internal and External Hard Drives Internal hard drives – Permanent storage devices located inside the system unit – Removed only if a problem develops External hard drives – Commonly used to transport large amounts of data from one computer to another – Portable external hard drives are smaller and easier to transport – Most connect with a USB connection although some may be wireless Understanding Computers: Today and Tomorrow, 15th 17 Edition  Internal and External Hard Drives Understanding Computers: Today and Tomorrow, 15th 18 Edition  Hard Drive Speed, Disk Caching, and Hybrid Hard Drives Disk access time – Total time that it takes for a hard drive to read or write data – Consists of seek time, rotational delay, and data movement time SSDs don’t require seek time or rotational delays Disk cache – Memory used in conjunction with a magnetic hard drive to improve system performance – Typically consist of memory chips on a circuit board inside the hard drive case Understanding Computers: Today and Tomorrow, 15th 19 Edition  Hard Drive Speed, Disk Caching, and Hybrid Hard Drives Hybrid Hard Drive – Combination of flash memory and magnetic hard drive – Uses flash memory for cache – Allows encryption to be built into the drive Understanding Computers: Today and Tomorrow, 15th 20 Edition  Hard Drive Partitioning and File Systems Partitioning – Divides the physical capacity of a single drive logically into separate areas, called partitions – Partitions function as independent hard drives – Referred to as logical drives – Increases efficiency (smaller drives use smaller clusters) Partitions used to create: – A recovery partition – A new logical drive for data – A dual boot system Understanding Computers: Today and Tomorrow, 15th 21 Edition  Hard Drive Partitioning and File Systems File system – Determines the partition size, cluster size, maximum drive size, and maximum file size FAT, FAT32, and NTFS Understanding Computers: Today and Tomorrow, 15th 22 Edition  Hard Drive Interface Standards Determine how a drive connects to the computer Common standards – Parallel ATA (PATA) - older, slower standard – Serial ATA (SATA) – eSATA – SCSI and the newer serial attached SCSI (SAS) – Fibre Channel – Fibre Channel over Ethernet (FCoE) – Internet SCSI (iSCSI) Understanding Computers: Today and Tomorrow, 15th 23 Edition  Quick Quiz 1.Of the following three options, the storage media that would likely hold the most data is a(n). a.internal hard drive b.USB flash memory drive c.portable hard drive 2.True or False: Hard drives typically contain more than one metal hard disk. 3.The circular rings on a magnetic disk on which data is stored are called. Understanding Computers: Today and Tomorrow, 15th 24 Edition  Optical Discs and Drives Optical Disc Characteristics – A type of storage read from and written to using laser beams – Today’s standard for software delivery – Divided into sectors like magnetic discs but use a single spiral track (groove) – Have a relatively large capacity and are durable – Used for backup purposes and for storing and transporting music, photos, video, etc. Understanding Computers: Today and Tomorrow, 15th 25 Edition  Optical Discs and Drives Representing Data on an Optical Disc – Read-only optical disc Surface of disc is molded or stamped – Recordable or rewritable disc Optical drive is used and the reflectivity of the disc is changed using a laser to represent the data – Pits and lands are used to represent 1s and 0s – The transition between a pit and a land represents a 1; no transition represents a 0 Understanding Computers: Today and Tomorrow, 15th 26 Edition  Optical Discs and Drives Understanding Computers: Today and Tomorrow, 15th 27 Edition  Optical Discs and Drives Optical Drives – Three categories of discs: CD, DVD, or Blu- Ray Disc (BD) – Can be read-only, recordable, or rewritable – Almost always downward compatible – Can support single or dual layer discs – Recording data onto disc is called burning – Can be internal or external drives External drives typically connect via USB port Understanding Computers: Today and Tomorrow, 15th 28 Edition  Optical Discs and Drives Optical Disc Shapes, Sizes, and Capacities – Standard size is 120-mm (about 4.7 inches) Mini discs are smaller—80-mm – Theoretically can be made into various shapes—hearts, triangles, irregular shapes, or a hockey-rink shape Patent battle exists about changing optical disc shapes None of these different shapes are currently available Understanding Computers: Today and Tomorrow, 15th 29 Edition  Optical Discs and Drives Major advantage: large capacity – CD discs are normally single layer and hold 650 or 700 MB – DVD discs hold 4.7 GB (single-layer) or 8.5 GB (dual-layer – BD discs hold 25 GB (single-layer) or 50 GB (dual-layer – Discs can also be double-sided – Researchers continually work to increase the capacity of optical discs DL and XL discs 4K (Ultra HD) Blu-ray Discs Understanding Computers: Today and Tomorrow, 15th 30 Edition  Optical Discs and Drives Understanding Computers: Today and Tomorrow, 15th 31 Edition  Read-Only Optical Discs CD ROM, DVD ROM, and BD-ROM – Can be read from, but not written to, by the user CD-ROM (compact disc read-only memory) DVD-ROM (digital versatile disc read-only memory) BD-ROM (Blu-Ray Disc read-only memory) – Normally come pre-recorded Software programs Clip art and other graphics MusicToday and Tomorrow, 15th Understanding Computers: 32 Edition  Recordable Optical Discs CD-R, DVD-R, DVD+R, BD-R Discs – Can be written to, but cannot be erased and reused – No physically molded pits – Most have a recording layer containing organic light- sensitive dye between disc’s plastic and reflective layers Except the BD-R disc, which has inorganic material – Used for backing up files, sending large files to others, and creating custom music CDs Understanding Computers: Today and Tomorrow, 15th 33 Edition  Rewritable Optical Discs CD-RW, DVD-RW, DVD+RW, and BD-RE Discs – Can be written to, but cannot be erased and reused Uses phase change technology – Heating and cooling process is used to change the reflectivity of the disc Capacities are identical to the read-only and recordable discs, except BDXL – Appropriate for transferring large files from one computer to another or temporarily storing TV shows Understanding Computers: Today and Tomorrow, 15th 34 Edition  Quick Quiz 1.The capacity of the typical CD disc is. a.50 GB b.700 MB c.4.7 GB 2.True of False: A DVD-RW disc can be written to and rewritten to. 3.The tiny depressions, dark areas, or otherwise altered spots on an optical disc that are used to represent data are called. Understanding Computers: Today and Tomorrow, 15th 35 Edition  Flash Memory Storage Systems Flash Memory – Chip-based storage medium that represents data using electrons – Used in SSDs and hybrid hard drives Embedded Flash Memory – Flash memory chips embedded into products, such as Portable digital media players, digital cameras Handheld gaming devices, GPS devices, mobile phones Sunglasses and wristwatches Understanding Computers: Today and Tomorrow, 15th 36 Edition  Flash Memory Storage Systems Understanding Computers: Today and Tomorrow, 15th 37 Edition  Flash Memory Storage Systems Flash Memory Cards and Readers – Flash memory card Small card containing one or more flash memory chips, a controller chip, and metal contacts to connect the card to the device or reader with which it is being used Available in various formats that are not interchangeable: CompactFlash Secure Digital (SD) xD Picture Card Memory Stick Secure Digital High Capacity (SDHC) MultiMedia Card Secure Digital Extended Capacity (MMC) (SDXC) Understanding Computers: Today and Tomorrow, 15th 38 Edition  Flash Memory Storage Systems Understanding Computers: Today and Tomorrow, 15th 39 Edition  Flash Memory Storage Systems General-purpose flash memory card – Appropriate for most applications Specialized flash memory cards – Professional flash memory cards Designed for professional photographers – Gaming flash memory cards Designed for gaming consoles – HD flash memory cards Designed for capturing and transferring high-definition video Understanding Computers: Today and Tomorrow, 15th 40 Edition  Flash Memory Storage Systems USB Flash Drives – Sometimes called flash memory drives, jump drives, or thumb drives – Flash memory media integrated into a self- contained unit that plug into and is powered by a USB port – Designed to be very small and very portable – Available in a host of formats including custom shapes – Can be built into a consumer product – Can be used to lock a computer and to issue Web site passwords – Can include biometric features, such Edition as a built-in fingerprint reader Understanding Computers: Today and Tomorrow, 15th 41  Flash Drive Storage Systems Understanding Computers: Today and Tomorrow, 15th 42 Edition  Other Types of Storage Systems Network Storage and Cloud Storage Systems – Remote storage Using a storage device not directly connected to the computer being used Accessed through the Internet or through a network – Network storage Remote storage via local network Understanding Computers: Today and Tomorrow, 15th 43 Edition  Network and Cloud Storage Systems Understanding Computers: Today and Tomorrow, 15th 44 Edition  Network and Cloud Storage Systems Cloud storage (online storage) – Accessed via the Internet Via Web sites (Facebook, Google Docs, etc.) Via online storage sites (Box, Dropbox, etc.) Growing in importance because more and more applications are Web based Increasing being used for backup purposes Files can be synched between PC and cloud storage Edition Many Web sites providing online Understanding Computers: Today and Tomorrow, 15th 45  Network and Cloud Storage Systems Understanding Computers: Today and Tomorrow, 15th 46 Edition  Smart Cards Smart Card – Credit card-sized piece of plastic that contains some computer circuitry (processor, memory, and storage) – Stores small amount of data (about 64 KB or less) – Commonly used to store prepaid amounts of digital cash or personal information – Smart card readers are built into or attached to a computer, door lock, vending machine, or other device – Some smart cards store biometric data Edition – Use of mobile smart cards is an emerging Understanding Computers: Today and Tomorrow, 15th 47  Smart Cards Understanding Computers: Today and Tomorrow, 15th 48 Edition  Holographic Storage Holographic storage – Holographic drives connect to a computer via a serial attached SCSI (SAS) or Fibre Channel interface – Uses multiple blue laser beams to store data in three dimensions Reference beam and signal beam – Suited to applications in which large amounts of data need to be stored or retrieved quickly but rarely changed Archiving business data, medical records, TV shows, Edition sensor Understanding Computers: data Today , etc. and Tomorrow, 15th 49  Storage Systems for Large Computer Systems Understanding Computers: Today and Tomorrow, 15th 50 Edition  Storage Systems for Large Computer Systems RAID (redundant arrays of independent discs) – Method of storing data on two or more hard drives that work together to do the job of a larger drive – Mostly used to protect critical data on large storage systems – Usually involves recording redundant copies of stored data – Helps to increase fault tolerance Understanding Computers: Today and Tomorrow, 15th 51 Edition  Storage Systems for Large Computer Systems Different levels of RAID: – RAID 0 = disk striping (spread files over two or more hard drives) – RAID 1 = disk mirroring (duplicate copy) – Other level use a combination or striping and mirroring Drobo system – New RAID storage system – Much easier to use than previous systems – Offers continuous data redundancy Understanding Computers: Today and Tomorrow, 15th 52 Edition  Storage Systems for Large Computer Systems Understanding Computers: Today and Tomorrow, 15th 53 Edition  Magnetic Tape Systems Magnetic Tape – Plastic tape coated with a magnetizable substance that represents the bits and bytes of digital data – Primarily used for backup and archival purposes – Sequential access only – Low cost per terabyte – Most tapes today are in the form of cartridge tapes Understanding Computers: Today and Tomorrow, 15th 54 Edition  Evaluating Your Storage Alternatives Product Characteristics to Consider: – Speed – Compatibility – Storage capacity – Convenience – Portability Most Users Require: – Hard drive – Recordable or rewritable optical drive – Flash memory card reader – USB Understanding ports Computers: Today and Tomorrow, 15th 55 Edition  Quick Quiz 1.An online photo sharing site is an example of. a.RAID b.cloud storage c.holographic storage 2.True or False: Flash memory storage systems are called solid- state storage systems because they are nonvolatile. 3.A type of sequential storage that sometimes used today for backup purposes is. Understanding Computers: Today and Tomorrow, 15th 56 Edition