The use of microfilm and microfiche provides all of the following advantages EXCEPT

Presentation on theme: "Chapter 7 Storage."— Presentation transcript:

1 Chapter 7 Storage

2 Access Time - Locate and Transfer data
Floppy Disk Small files to be transported Secondary Storage Primary Storage Hard Disk CDs and DVDs Miniature Storage Media Tape Items waiting to be interpreted and executed by processor Operating system, application software, user data and information Software, backups, movies, music Digital pictures or small files to be transported Backups Memory (RAM) Stores Faster Transfer Rates Slower Transfer Rates

3 Storage What is storage?
Holds data, instructions, and information for future use Storage medium is physical material used for storage Also called secondary storage p Fig. 7-1 Next

4 Storage A storage device is the computer hardware that records and/or retrieves items to and from storage media 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 Page 354

5 Capacity Number of Bytes Medium can Hold NAME AMOUNT NUMBER Kilobyte
1 Thousand 1,000 Megabyte 1 Million 1,000,000 Gigabyte 1 Billion 1,000,000,000 Terabyte 1 Trillion 1,000,000,000,000 Petabyte 1 Quadrillion 1,000,000,000,000,000 Exabyte 1 Quintillion 1,000,000,000,000,000,000 Zettabyte 1 Sextillion 1,000,000,000,000,000,000,000 Yottabyte 1 Septillion 1,000,000,000,000,000,000,000,000 MB = 700+ pages; GB = 262 ft of pages; TB = 51 miles of paper; PB = ¼ distance to moon MB = 700+ pages GB = 262 ft of pages TB = 51 miles of papers PB = ¼ distance to moon

6 would be equal to all of the words ever spoken by mankind.
Petabyte: A Petabyte is approximately 1,000 Terabytes or one million Gigabytes. It's hard to visualize what a Petabyte could hold. 1 Petabyte could hold approximately 20 million 4-drawer filing cabinets full of text. It could hold 500 billion pages of standard printed text. It would take about 500 million floppy disks to store the same amount of data. Supercomputer hard disk=PB Exabyte: An Exabyte is approximately 1,000 Petabytes. Another way to look at it is that a Petabyte is approximately one quintillion bytes or one billion Gigabytes. There is not much to compare an Exabyte to. It has been said that 5 Exabytes would be equal to all of the words ever spoken by mankind. Zettabyte: A Zettabyte is approximately 1,000 Exabytes. There is nothing to compare a Zettabyte to but to say that it would take a whole lot of ones and zeroes to fill it up. Yottabyte: A Yottabyte is approximately 1,000 Zettabytes. Again, there is nothing to compare a Yottabyte with.

7 Capacity Average Enterprise Storage Capacity 412TB
San Diego Supercomputer Centre (SDSC) at the University of California, San Diego, 36 PB as of 2/25/09 Largest Archival Storage Capacity of any Educational Site

8 Storage How does volatility compare?
Storage medium is nonvolatile—contents retained when power is off Memory is volatile—holds data and instructions temporarily ON OFF Memory (most RAM) (chips on motherboard) Screen Display Display appears Display disappears Volatile Data and instructions available to user Data and instructions erased Storage Medium (USB, DVD’s , hard disks, CDs) Nonvolatile Contents available to user Contents retained p. 356 Next

9 a. Storage c. Throughput b. Output d. Input
____ holds data, instructions, and information for future use. a. Storage c. Throughput b. Output d. Input

10 ______ storage is the physical material on which
a computer keeps data, instructions, and information. a. Primary c. Tertiary b. Secondary d. all of the above

11 a. Resolution c. Capacity b. Dimensionality d. Retention
_______ is the number of bytes (characters) a storage medium can hold. a. Resolution c. Capacity b. Dimensionality d. Retention

12 a. concatenation c. resolved b. indexed d. storage
A(n) ____ device is the computer hardware that records and/or retrieves items to and from storage media. a. concatenation c. resolved b. indexed d. storage

13 Disk References 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

14 Magnetic Media Floppy Disk Original PC Storage Portable Inexpensive
Shutter Shell Liner Magnetic Coating Flexible Thin Film Metal Hub

15 Hard Disks A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions, and information

16 Magnetic Media Formatting Preparing Disk for Reading & Writing Track
Circular Band on Disk Surface Sector Pie-shaped Bad Sectors Marked as Unusable

17 Magnetic Disks What are tracks and sectors? FAT
Track is narrow recording band that forms full circle on disk Sector stores up to 512 bytes of data FAT Formatting prepares disk for use p. 357 Fig. 7-5 Next

18 File Systems FAT 32 Support for hard drives up to 2 TB
FAT or FA T 16 Support for hard drives up to 2 GB Cluster size was 32K – killed 64 sectors 8.3 file names VFAT byte file names – Windows 95 FAT 32 Support for hard drives up to 2 TB Cluster size is 4K to 16K - killed sectors NTFS Cluster size is 4K to 16K Support for drives up to 256 TB More protection if system crashes Debate: Smaller clusters or larger clusters: 2K vs. 4K?

19 Clusters 4K for hard drives from 2GB to 16 TB

20 Magnetic Disks How does a hard disk work?
How does a hard disk work? Step 3. When software requests a disk access, read/write heads determine current or new location of data. Step 2. Small motor spins platters while computer is running. Step 4. Head actuator positions read/write head arms over correct location on platters to read or write data. Step 1. Circuit board controls movement of head actuator and a small motor. p. 360 Fig. 7-8 Next

21 Magnetic Media Head Crash Spinning Creates Air Cushion Crash
Floats Read / Write Head Above Platter Crash Head Touches Platter Surface Clearance = Two-millionths of an Inch Read/Write Head Platter Hair Dust Smoke

22 Hard Disks –Cylinder Method of Storage
track What is a cylinder? Location of a single track through all platters Single movement of read/write head arms can read same track on all platters

23 Hard Disks The hard disk arms move the read/write head, which reads items and writes items in the drive Location often is referred to by its cylinder

24 Sample Hard Disk Characteristics
Magnetic Disks What are characteristics of a hard disk? Sample Hard Disk Characteristics Advertised capacity 500 GB Platters 4 Read/write heads 8 Cylinders 16,383 Bytes per sector 512 Sectors per track 63 Sectors per drive 973,773,168 Revolutions per minute 7,200 Transfer rate MB per second Access time 8.5 ms actual disk capacity Vista Home and Defrag p. 359 Fig. 7-7 Next

25 Operating System Utility Programs
What is a disk defragmenter? Reorganizes files and unused space on hard disk so programs run faster p. 414 Fig. 8-19 Next

26

27 hard disk mounted in system unit
Magnetic Disks hard disk mounted in system unit What is a hard disk? High-capacity storage Consists of several inflexible, circular platters that store items electronically Components enclosed in airtight, sealed case for protection Longitudinal recording Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Perpendicular Recording below Chapter 7 Perpendicular recording p. 358 Fig. 7-6 Next

28 Perpendicular Storage
The storage industry currently makes hard drives using longitudinal recording, which is reaching its physical limit. With this method, bits of data are arranged horizontally on the recording magnetic medium. Perpendicular recording methods arrange bits vertically so more can fit on, and higher recording densities can be achieved without magnetic interference which can corrupt data. This method should mean hard drive storage based on moving mechanical parts will be around for another 20 years or so, says Mr Pait.

29 Perpendicular Storage
Click on Get Perpendicular animation

30 Terabyte Living Mr Pait thinks that …
in about five years PCs will have five terabytes of storage on board. One terabyte is the equivalent of 1,024GB enough to hold more than 240,000 songs at the standard encoding rate for digital music files. June 11, 2005

31 Hard Disks An external hard disk is a separate free-standing hard disk that connects to your computer with a cable or wirelessly A removable hard disk is a hard disk that you insert and remove from a drive Internal and external hard disks are available in miniature sizes (miniature hard disks)

32 Magnetic Disks What is a disk cache?
Don’t confuse this cache with portion of memory that processor uses to store frequently accessed items first request for data—to disk cache Memory cache on motherboard to RAM to disk cache on hard drive to hard drive platters Short for Level 2 caching, L2 is also commonly referred to as secondary cache or external cache. Unlike Layer 1 cache, L2 cache is commonly located on the motherboard, although with most new processors it is being found on the processor. When L2 cache is found on the processor, if cache is found on the motherboard, it is properly known as L3 cache. second request for data—to hard disk Memory cache on motherboard to RAM (main memory on motherboard) to disk cache on hard drive to hard drive platters p. 361 Fig. 7-11

33 More about caches

34 The inflexible, circular platters on ____ disks use
magnetic particles to store data, instructions, and information on a disk’s surface. a. hard c. optical b. digital d. indexed

35 a. cluster c. bit b. allocation unit d. integer
The smallest unit of data a computer can process is a(n) ____. a. cluster c. bit b. allocation unit d. integer

36 a. Indexing c. Recording b. Formatting d. Elongating
____ is the process of dividing a disk into tracks and sectors, so the operating system can store and locate data and information on the disk. a. Indexing c. Recording b. Formatting d. Elongating

37 A(n) ____ is made of aluminum, glass, or
ceramic and is coated with an alloy material that allows items to be recorded magnetically on its surface. a. sector c. vector b. read/write head d. platter

38 All of the following are characteristics of hard disks
EXCEPT ____. a. write-protect notch c. sectors and tracks b. read/write head d. capacity

39 Some computers improve hard disk access time by
using a disk ____, which consists of memory chips that store frequently accessed items. a. warehouse c. base b. cache d. home

40 Cloud Storage Cloud storage is an Internet service that provides storage to computer users

41 Cloud Storage

42 Cloud Storage Users subscribe to cloud storage for a variety of reasons: 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

43 Miniature Mobile Storage Media
What is a USB Flash Drive? Plugs in a USB port on a computer or mobile device Storage capacities up to 64 GB Has made the floppy disk obsolete May make hard drive obsolete Moore’s Law ????? Next

44 Kingston 256GB USB This 256GB USB drive offers highest storage capacity presently. (July - 26 – 2009)

45 Generate less heat and consume less power
Solid State Drives Solid state media use flash memory chips and contain no moving parts GB with 1.2TB (Moore’s Law) Solid state drives (SSDs) have several advantages over magnetic hard disks: Faster access time Faster transfer rates Generate less heat and consume less power Last longer June 8, Capacity has doubled to 640GB with 1.2TB planned for the 2nd half of 2009.

46 Solid State Drives Next Generation

47 Optical Discs What are optical discs?
Push the button to slide out the tray. Flat, round, portable metal discs made of metal, plastic, and lacquer Insert the disc, label side up. Can be read only or read/write Most PCs include an optical disc drive Push the same button to close the tray. p. 366 Fig. 7-17 Next

48 Optical Discs How does a laser read data on an optical disc?
laser diode prism light- sensing diode 1 lens pit land disc label Step 3. Reflected light is deflected to a light-sensing diode, which sends digital signals of 1 to computer. Absence of reflected light is read as digital signal of 0. Step 2. If light strikes a pit, it scatters. If light strikes a land, it is reflected back toward diode. Step 1. Laser diode shines a light beam toward disc. p. 367 Fig. 7-18 Next

49 Optical Discs How is data stored on an optical disc?
Typically stored in single track Track divided into evenly sized sectors that store items single track spirals to edge of disc disc sectors p. 367 Fig. 7-19 Next

50 Optical Discs How should you care for an optical disc?
p. 368 Fig. 7-20 Next

51 Optical Discs What is a CD-ROM? Compact disc read-only memory
Same technology as audio CD’s Cannot erase or modify contents Typically holds 650 MB to 1 GB Commonly used to distribute software and games Next

52 Ranges from 48X to 75X or faster 75X is 150 KBps (KB per second)
Optical Discs What is the data transfer rate of a CD-ROM drive? Ranges from 48X to 75X or faster 75X 75  150 KBps = 11,250 KBps or MBps 75X is 150 KBps (KB per second) 48X: 48  150 KBps = 7,200 KBps or 7.2 MBps p. 369 Next

53 DVD Transfer Rates DVD Read/Write Speed Transfer Rate bytes/sec
Transfer Rate KB/sec Transfer Rate MB/sec Equivalent CD-R/CD-RW read/ write speed 1x 1,385,000 1,352.54 1.32 9x 2x 2.770,000 2,705.08 2.64 18x 3x 4,155,000 4,057.62 3.96 27x 4x 5,540,000 5,410.16 5.28 36x 5x 6,925,000 6,762.70 6.60 45x 6x 8,310,000 8,115.23 7.93 54x 8x 11,080,000 10,820.31 10.57 -- 10x 13,850,000 13,525.39 13.21 12x 16,620,000 16,230.47 15.85 16x 22,160,000 21,640.63 21.13

54 Optical Discs DVD Formats Explained
A CD-ROM can be read from but not written to Read from a CD-ROM drive or CD-ROM player A CD-R is a multisession optical disc on which users can write, but not erase A CD-RW is an erasable multisession disc Must have a CD-RW drive

55 Optical Discs Junk Closet A DVD-ROM is a high-capacity optical disc on which users can read but not write or erase Requires a DVD-ROM drive A Blu-ray Disc-ROM (BD-ROM) has a storage capacity of 100 GB DVD-RW, DVD+RW, and DVD+RAM are high-capacity rewritable DVD formats -- Hybrid (DVD±RW) drives

56 How should you care for a DVD?
U:\WEBSITE\PEOPLE\FACULTY\zlotow\PP Slides\DVDCare.htm

57 Optical Discs Junk Closet What is a DVD-ROM (digital versatile disc-ROM used to be digital video disc) Must have DVD-ROM drive or DVD player to read DVD-ROM Stores databases, music, complex software, and movies Blu-ray discs (BD) have storage capacity of up to 100 GB HD-DVD discs have storage capacity of up to 60 GB UMD can store up to 1.8 GB LOTR Lord of the Rings 12.5MB per Frame 24 Frames per Second 3+ GB per Movie UMD developed by Sony as first optical disc format to be used for a handheld video game system-- Playstation Next

58 Optical Discs How does a DVD-ROM store data?
Two layers of pits are used, lower layer is semitransparent so laser can read through Some are double-sided Many types of recordable and rewritable DVDs are available DVD-R and DVD+R DVD-RW and DVD+RW BD is commonly known as a Blue-ray disc. p Fig. 7-25 Next

59 Users subscribe to a cloud storage service to ______ .
save time by storing large files instantaneously b. allow others to access files c. store offsite backups of data d. all of the above

60 A(n) ____ disc is a type of storage media that
consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser. a. magnetic c. laser-ready b. solid-state d. optical

61 Microfilm and microfiche
Other Types of Storage Tape Microfilm and microfiche

62 The drive designation of an optical disc drive
usually ____. a. precedes alphabetically before that of all the hard disks b. comes alphabetically between that of the hard disks c. follows alphabetically after that of all the hard disks d. none of the above

63 A(n) ____ is a type of optical disc that users can
read but not write or erase. a. CD-R c. DVD-ROM b. CD-RW d. DVD-RW

64 A typical CD-ROM holds from ____ of data,
instructions, and information. a. 450 MB MB c. 650 GB GB b. 45 MB MB d. 650 MB - 1 GB

65 A storage technique that a DVD-ROM can use to
achieve a higher storage capacity than a CD-ROM is to ________. a. make the disc more dense by packing the pits closer together b. use two layers of pits c. be double-sided d. all of the above

66 Tape What is tape? Magnetically coated plastic ribbon capable of storing large amounts of data at low cost Primarily used for backup Web site for tape drives p. 374 Fig. 7-27 Next

67 Tape How is data stored on a tape? Sequential access Direct access
Reads and writes data consecutively — used for music tapes or VHS Direct access Locates a file immediately— used for hard disks, CDs, and DVDs p. 374 Next

68 Microfilm and Microfiche
What are microfilm and microfiche? Store microscopic images of documents on roll or sheet of film Microfilm — 100- to 215-foot roll of film Microfiche — small sheet of film, usually 4”  6” p. 379 Fig. 7-34 Next

69 Microfilm and Microfiche
Who uses microfilm and microfiche? 1. Libraries for back issues 2. Banks for cancelled checks 3. Archival of inactive files 4. US Army for personnel records What are the advantages of microfilm and microfiche? 1. Reduce amount of paperwork 2. Inexpensive 3. Longest life of any storage media Next

70 Microfilm and Microfiche
How do life expectancies of various media compare? Microfilm and microfiche have longest life of any storage media p. 379 Fig. 7-35 Next

71 Tape _________. a. no longer is used as a primary method of storage but is used most often for long-term storage and backup b. is used as a primary method of storage and for long-term storage and backup c. no longer is used for long-term storage and backup but is used most often as a primary method of storage d. no longer is used as a primary method of storage or for long-term storage and backup

72 All of the following use direct access except ____.
CDs c. tape b. DVDs d. hard disks

73 ____ is a magnetically coated ribbon of plastic
capable of storing large amounts of data and information at a low cost. a. Tape c. Indexed data b. Opticon d. Threaded memory

74 Tape storage requires ____ access, which refers to
reading or writing data consecutively. a. consequential c. inferential b. tangential d. sequential

75 ____ is a small sheet of film, usually about 4 inches
by 6 inches, that stores microscopic images of documents. a. Microfilm c. Microfiche b. Microtape d. Microsheet

76 The use of microfilm and microfiche provides all of
the following advantages except ____. a. they greatly reduce the amount of paper firms must handle b. they are inexpensive c. they have the longest life of any storage media d. they can be read without a microfilm or microfiche reader

Which of the following is a storage technique that a DVD ROM can use to achieve a higher storage capacity than a CD

Which of the following is a good practice to follow to avoid scratching or damaging a disc?

Which of the following disc types can be written on but not erased?

What kind of storage is an Internet service that provides storage to computer or mobile users?