Week 1


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Week 1

  1. 1. Linux+ Guide to Linux Certification, Second Edition Chapter 1 Introduction to Linux
  2. 2. Operating Systems <ul><li>Computers have two fundamental components: </li></ul><ul><ul><li>Hardware: Physical components inside a computer </li></ul></ul><ul><ul><li>Software: Set of instructions or programs that understand how to use the hardware of the computer in a meaningful way </li></ul></ul>
  3. 3. Operating Systems (continued) <ul><li>Hardware components include: </li></ul><ul><ul><li>Processor (CPU) </li></ul></ul><ul><ul><li>Physical memory (RAM) </li></ul></ul><ul><ul><li>Hard disk, floppy disk, and CD-ROM drives </li></ul></ul><ul><ul><li>Sound and video cards </li></ul></ul><ul><ul><li>Circuit boards </li></ul></ul>
  4. 4. Operating Systems (continued) <ul><li>Two different types of programs are executed on a computer: </li></ul><ul><ul><li>Applications </li></ul></ul><ul><ul><li>Operating system (OS) software </li></ul></ul><ul><li>Device Driver: Software containing instructions that the OS uses to control and interact with a specific type of computer hardware </li></ul><ul><li>User Interface: An application program that allows the user to interact with the OS and other application programs </li></ul>
  5. 5. Operating Systems (continued) Figure 1-1: The role of operating system software
  6. 6. Operating Systems (continued) <ul><li>Graphical user interface (GUI): Component of an OS that provides a user-friendly interface </li></ul><ul><li>System services: Applications that handle system-related tasks </li></ul><ul><ul><li>Printing </li></ul></ul><ul><ul><li>Scheduling programs </li></ul></ul><ul><ul><li>Network access </li></ul></ul>
  7. 7. Operating Systems (continued) Figure 1-2: A Linux graphical user interface
  8. 8. The Linux Operating System <ul><li>OS used to run a variety of applications on a variety of different hardware </li></ul><ul><li>Has the ability to manage thousands of tasks at the same time </li></ul><ul><li>Allows multiple users to access the system simultaneously </li></ul><ul><ul><li>Multiuser and multitasking OS </li></ul></ul>
  9. 9. Versions of the Linux Operating System <ul><li>Core component is called the Linux kernel </li></ul><ul><ul><li>Written almost entirely in the C programming language </li></ul></ul><ul><li>Software can be used to modify appearance of Linux, but the kernel is common to all Linux </li></ul>
  10. 10. Identifying Kernel Versions <ul><li>Linux kernel versions are composed of: </li></ul><ul><ul><li>Major number </li></ul></ul><ul><ul><li>Minor number </li></ul></ul><ul><ul><ul><li>If odd, referred to as a developmental kernel </li></ul></ul></ul><ul><ul><ul><li>If even, referred to as a production kernel </li></ul></ul></ul><ul><ul><li>Revision number </li></ul></ul>
  11. 11. Identifying Kernel Versions (continued) Table 1-1: Latest revisions of common Linux kernels
  12. 12. Licensing Linux <ul><li>Open Source Software (OSS): Programs distributed and licensed so that the source code is available to anyone who wants to examine, utilize, or improve upon it </li></ul><ul><ul><li>Format and structure of source code follows rules defined by the programming language in which it was written </li></ul></ul>
  13. 13. Licensing Linux (continued) <ul><li>Implications of OSS: </li></ul><ul><ul><li>Developed very rapidly through widespread collaboration </li></ul></ul><ul><ul><li>Bugs (errors) are noted and promptly fixed </li></ul></ul><ul><ul><li>Features evolve quickly based on users’ needs </li></ul></ul><ul><ul><li>Perceived value of the software increases because it is based on usefulness, not on price </li></ul></ul>
  14. 14. Licensing Linux (continued) Table 1-2: Software types
  15. 15. Types of Closed Source Licenses <ul><li>Most closed source software is sold commercially </li></ul><ul><ul><li>e.g., Microsoft or Electronic Arts software </li></ul></ul><ul><li>Freeware: Distributed free of charge; source code is not available </li></ul><ul><li>Shareware: Initially free, but requires payment after a period of time or usage </li></ul>
  16. 16. Linux Advantages: Meeting Business Needs <ul><li>Common software available for Linux includes: </li></ul><ul><ul><li>Scientific and engineering software </li></ul></ul><ul><ul><li>Software emulators </li></ul></ul><ul><ul><li>Web servers, Web browsers, and e-commerce suites </li></ul></ul><ul><ul><li>Desktop productivity software </li></ul></ul><ul><ul><li>Graphics manipulation software </li></ul></ul><ul><ul><li>Database software </li></ul></ul><ul><ul><li>Security software </li></ul></ul>
  17. 17. Linux Advantages: Ease of Customization <ul><li>Ability to control the inner workings of an OS </li></ul><ul><ul><li>To use Linux as an Internet Web server, compile the kernel to include only the support needed to be an Internet Web server </li></ul></ul><ul><ul><ul><li>Results in a much smaller and faster kernel </li></ul></ul></ul>
  18. 18. Linux Advantages: Ease of Obtaining Support <ul><li>Linux documentation can be found on the Internet </li></ul><ul><ul><li>Frequently Asked Questions (FAQs) </li></ul></ul><ul><ul><li>HOWTO documents </li></ul></ul><ul><li>Linux Newsgroups </li></ul><ul><li>Linux User Group (LUG): Open forum of Linux users who discuss and assist each other in using and modifying the Linux OS </li></ul>
  19. 19. Linux Advantages: Cost Reduction Table 1-3: Calculating the total cost of ownership
  20. 20. The History of Linux Figure 1-4: Timeline of UNIX and Linux development
  21. 21. UNIX <ul><li>Evolved from Multiplexed Information and Computing Service (MULTICS) </li></ul><ul><li>The first true multitasking, multiuser OS </li></ul><ul><li>Written in the C programming language </li></ul><ul><ul><li>Portable OS </li></ul></ul><ul><li>OS from which Linux originated </li></ul>
  22. 22. UNIX (continued) <ul><li>Berkeley Software Distribution (BSD) </li></ul><ul><ul><li>Version of the original UNIX source code </li></ul></ul><ul><li>Common flavors of UNIX today include: </li></ul><ul><ul><li>Sun Microsystems’s Solaris </li></ul></ul><ul><ul><li>Hewlett-Packard’s HP-UX </li></ul></ul><ul><ul><li>IBM’s AIX UNIX </li></ul></ul>
  23. 23. Linux <ul><li>First developed by Linus Torvalds in 1991 </li></ul><ul><ul><li>Published under the GNU license </li></ul></ul><ul><li>Linux kernel developed collaboratively and centrally managed </li></ul><ul><ul><li>Linux is simply a by-product of OSS development </li></ul></ul>
  24. 24. Linux Distributions <ul><li>Red Hat and SuSE </li></ul><ul><li>Distributions may appear different on the surface, but run the same kernel </li></ul><ul><li>Most distributions ship with a GUI that can be further customized to suit needs of the user </li></ul><ul><ul><li>Core component of this GUI is X Windows </li></ul></ul>
  25. 25. Linux Distributions (continued) <ul><li>GUI environment: X Windows in combination with a window manager and desktop environment </li></ul><ul><li>Two competing GUI environments in Linux: </li></ul><ul><ul><li>GNU Object Model Environment (GNOME) </li></ul></ul><ul><ul><li>Kommon Desktop Environment (KDE) </li></ul></ul>
  26. 26. Linux Distributions (continued) Figure 1-5: The GNOME Desktop
  27. 27. Common Uses of Linux <ul><li>May be customized to provide services for a variety of companies in a variety of situations </li></ul><ul><li>Workstation services: Services used on a local computer </li></ul><ul><li>Server services: Services made available for other computers across a network </li></ul>
  28. 28. Internet Servers: Mail Services <ul><li>Mail transfer agent (MTA): An e-mail server </li></ul><ul><li>Mail delivery agent (MDA): Service that downloads e-mail from an MTA </li></ul><ul><li>Mail user agent (MUA): Program that allows e-mail to be read by a user </li></ul>
  29. 29. Internet Servers: Routing and FTP Services <ul><li>Routing: Provides interconnection between separate networks </li></ul><ul><ul><li>Core service necessary for Internet to function </li></ul></ul><ul><ul><li>Linux provides support for routing and is easily customizable </li></ul></ul><ul><li>File Transfer Protocol (FTP) Services: Most common and efficient method for transferring files over the Internet </li></ul>
  30. 30. Internet Servers: Firewalls and Proxy Services <ul><li>Firewall: Protects companies from outside intruders on the Internet </li></ul><ul><ul><li>Linux has firewall support built into the kernel </li></ul></ul><ul><li>Proxy server: requests Internet resources such as Web sites and FTP sites on behalf of the computer inside the company </li></ul>
  31. 31. Internet Servers: Web Services and News Services <ul><li>Web services: Web servers host information (text, pictures, music, binary data, and video) </li></ul><ul><ul><li>Can also process programs known as Common Gateway Interface (CGI) scripts and provide secure connections </li></ul></ul><ul><li>News services: News servers allow users to post messages in forums called newsgroups </li></ul><ul><ul><li>Most Web servers do not provide means for users to communicate </li></ul></ul>
  32. 32. Internet Servers: DNS Services <ul><li>Computers communicating on a network need to be uniquely identified </li></ul><ul><ul><li>Each computer is assigned an Internet Protocol (IP) address </li></ul></ul><ul><ul><ul><li>Long string of numbers </li></ul></ul></ul><ul><ul><ul><li>Allows computers to identify and reference each other </li></ul></ul></ul><ul><li>Fully Qualified Domain Name (FQDN): Masks IP addresses with user-friendly names </li></ul>
  33. 33. File and Print Servers <ul><li>Linux is well-suited for centrally sharing resources </li></ul><ul><ul><li>More economical to share files and printers over a network </li></ul></ul><ul><ul><li>Inherently fast and light </li></ul></ul><ul><ul><li>A distribution specific to a certain task can be installed on the central server </li></ul></ul>
  34. 34. Application Servers <ul><li>Application server: Intermediary between a client computer and a database </li></ul><ul><li>Database: Organized collection of data that is arranged into tables of related information </li></ul><ul><li>Database Management Systems (DBMS): Set of programs designed for creation, modification, manipulation, maintenance, and access of information from databases </li></ul>
  35. 35. Linux+ Guide to Linux Certification, Second Edition Chapter 2 Preparing for Linux Installation
  36. 36. Objectives <ul><li>Describe common types of hardware and their features </li></ul><ul><li>Obtain the hardware and software information necessary to install Linux </li></ul>
  37. 37. Understanding Hardware: Central Processing Units (CPUs) <ul><li>Core component of any computer </li></ul><ul><ul><li>Also known as microprocessor or processor </li></ul></ul><ul><li>Two main components: </li></ul><ul><ul><li>Arithmetic logic unit (ALU): Mathematical calculations and logic-based operations executed here </li></ul></ul><ul><ul><li>Control unit (CU): Instruction code or commands loaded and carried out here </li></ul></ul>
  38. 38. Understanding Hardware: CPUs (continued) <ul><li>Processor architecture: Arrangement of a processor’s integral electronics </li></ul><ul><li>Two main processor architectures: </li></ul><ul><ul><li>Complex Instruction Set Computer (CISC) </li></ul></ul><ul><ul><li>Reduced Instruction Set Computer (RISC) </li></ul></ul>
  39. 39. Understanding Hardware: CPUs (continued) <ul><li>Clock speed: Internal time cycle of a processor </li></ul><ul><ul><li>Determines speed that processor executes commands </li></ul></ul><ul><ul><li>Measured in Megahertz (MHz) </li></ul></ul><ul><li>A processor may require one cycle to complete a command or may be superscalar </li></ul><ul><li>Amount of information a processor can process at one time is a major factor in clock speed </li></ul><ul><ul><li>Measured in binary digits (bits) </li></ul></ul><ul><ul><li>The more information that can be worked on at once, the faster data can be manipulated </li></ul></ul>
  40. 40. Understanding Hardware: CPUs (continued) <ul><li>Cache: Temporary store of information </li></ul><ul><ul><li>Cache size and location affect a processor’s ability to calculate larger volumes of data </li></ul></ul><ul><li>Level 1 (L1) cache: Cache stored in the processor itself </li></ul><ul><li>Level 2 (L2) cache: Cache stored in a separate computer chip </li></ul><ul><ul><li>Connected to processor via high speed link </li></ul></ul><ul><li>Level 3 (L3) cache: Cache stored on a separate computer chip </li></ul><ul><ul><li>Connected directly to processor </li></ul></ul>
  41. 41. Understanding Hardware: CPUs (continued) <ul><li>Multiple processors can work together </li></ul><ul><ul><li>Perform the same tasks faster </li></ul></ul><ul><ul><li>Symmetric Multi-Processing (SMP): Allows OS and memory to use both processors simultaneously for any task </li></ul></ul><ul><ul><li>ASymmetric Multi-Processing (ASMP): Each processor given a set of tasks to complete independently </li></ul></ul>
  42. 42. Understanding Hardware: Physical Memory <ul><li>Storage area for information that is directly wired through circuit boards to the processor </li></ul><ul><li>Two main categories: </li></ul><ul><ul><li>Random Access Memory (RAM) </li></ul></ul><ul><ul><ul><li>Volatile memory </li></ul></ul></ul><ul><ul><li>Read Only Memory (ROM) </li></ul></ul>
  43. 43. Understanding Hardware: Physical Memory ― RAM <ul><li>Requires constant supply of electricity to maintain stored information </li></ul><ul><li>Directly related to computer performance </li></ul><ul><li>Two major categories: </li></ul><ul><ul><li>Dynamic RAM (DRAM) </li></ul></ul><ul><ul><li>Static RAM (SRAM) </li></ul></ul>
  44. 44. Understanding Hardware: Physical Memory ― RAM (continued) <ul><li>Three main types of DRAM sticks: </li></ul><ul><ul><li>Single In-line Memory Modules (SIMM) </li></ul></ul><ul><ul><ul><li>No longer produced </li></ul></ul></ul><ul><ul><li>Dual In-line Memory Modules (DIMM) </li></ul></ul><ul><ul><li>Small Outline Dual In-line Memory Modules (SODIMM) </li></ul></ul><ul><ul><ul><li>Used in portable notebook computers and Macintosh systems </li></ul></ul></ul>
  45. 45. Understanding Hardware: Physical Memory ― RAM (continued) <ul><li>Three recent DIMM technologies: </li></ul><ul><ul><li>Synchronous Dynamic Random Access Memory (SDRAM) </li></ul></ul><ul><ul><li>Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM) </li></ul></ul><ul><ul><li>Rambus Dynamic Random Access Memory (RDRAM) </li></ul></ul>
  46. 46. Understanding Hardware: Physical Memory ― ROM <ul><li>Read-only Memory: Physical memory that can be read but not written to </li></ul><ul><ul><li>Nonvolatile </li></ul></ul><ul><li>Basic Input/Output System (BIOS) ROM: Stores programs used to initialize hardware components when starting computer </li></ul>
  47. 47. Understanding Hardware: Physical Memory ― ROM Variants <ul><li>Programmable Read Only Memory (PROM): Can only be written to once </li></ul><ul><li>Erasable Programmable Read Only Memory (EPROM): Contents can be repeatedly erased and rewritten as a whole </li></ul><ul><li>Electronically Erasable Programmable Read Only Memory (EEPROM): Whole or partial contents can be repeatedly erased/rewritten </li></ul>
  48. 48. Understanding Hardware: Disk Drives <ul><li>Most information in a computer maintained using nonvolatile media, not consisting of integrated circuits </li></ul><ul><ul><li>Hard disk </li></ul></ul><ul><ul><li>Floppy disk </li></ul></ul><ul><ul><li>CD-ROM, DVD </li></ul></ul><ul><ul><li>CD-RW, DVD-RW disk </li></ul></ul><ul><ul><li>Zip disk </li></ul></ul><ul><ul><li>Flash Memory </li></ul></ul>
  49. 49. Understanding Hardware: Disk Drives ― Hard Disk Drives <ul><li>Not directly wired to the processor </li></ul><ul><ul><li>Pass through a hard disk controller card </li></ul></ul><ul><ul><ul><li>Controls flow of information to and from the hard disk drive (HDD) </li></ul></ul></ul><ul><li>Two types of controller cards: </li></ul><ul><ul><li>Integrated Drive Electronics (IDE) </li></ul></ul><ul><ul><ul><li>Also known as Advanced Technology Attachment (ATA) controllers </li></ul></ul></ul><ul><ul><li>Small Computer System Interface (SCSI) </li></ul></ul>
  50. 50. Understanding Hardware: Disk Drives ― HDDs (continued) Table 2-1: IDE HDD configurations
  51. 51. Understanding Hardware: Disk Drives ― HDDs (continued) <ul><li>Partitions: Small, manageable sections of a hard drive </li></ul><ul><li>Filesystems: Specify how data should reside on the hard disk itself </li></ul><ul><ul><li>A partition must be formatted with a filesystem </li></ul></ul>
  52. 52. Understanding Hardware: Disk Drives ― HDDs (continued) <ul><li>Primary partitions: Major unique and separate HDD divisions </li></ul><ul><li>Extended partitions: Partitions that can be further subdivided into logical drives </li></ul><ul><li>Master Boot Record (MBR): Table of all partition information for a hard disk </li></ul><ul><ul><li>Stored outside of all partitions </li></ul></ul>
  53. 53. Understanding Hardware: Disk Drives ― HDDs (continued) Table 2-2: Example partitioning scheme for a primary master IDE HDD
  54. 54. Understanding Hardware: Disk Drives ― Other Information Storage Devices <ul><li>Removable media: Information storage media that can be removed from the computer </li></ul><ul><ul><li>Transferable between computers </li></ul></ul><ul><li>Floppy disks: Store information electro-magnetically </li></ul><ul><ul><li>Used in floppy disk drives </li></ul></ul><ul><li>Zip disks: Similar to floppy disks </li></ul><ul><ul><li>Can store much more information </li></ul></ul><ul><ul><li>Used in zip drives </li></ul></ul>
  55. 55. Understanding Hardware: Disk Drives ― Other Information Storage Devices (continued) <ul><li>DVDs and CD-ROMs: Use lasers to read reflected light pulses </li></ul><ul><ul><li>Greater data transfer speed </li></ul></ul><ul><ul><li>Larger storage capacity </li></ul></ul><ul><ul><li>More resistance to data loss than floppy disks or ZIP disks </li></ul></ul><ul><li>Flash memory drives: Use EEPROM chips to store information </li></ul>
  56. 56. Understanding Hardware: Mainboards and Peripheral Components <ul><li>Bus: Pathway information takes from one hardware device to another via a mainboard </li></ul><ul><li>Mainboard (also called a motherboard): Circuit board that connects all other hardware components together via slots or ports on the circuit board </li></ul><ul><li>Peripheral components: Attach to the mainboard of a computer </li></ul><ul><ul><li>e.g., video cards, sound cards, and network interface cards (NICs) </li></ul></ul><ul><ul><li>Connected via an Input/Output bus represented by different slots or ports on the mainboard </li></ul></ul>
  57. 57. Understanding Hardware: Mainboards and Peripheral Components (continued) <ul><li>Three common slots for peripheral devices: </li></ul><ul><ul><li>Industry Standard Architecture (ISA): Information transfer at 8 MHz </li></ul></ul><ul><ul><li>Peripheral Component Interconnect (PCI): Information transfer at 33 MHz </li></ul></ul><ul><ul><ul><li>Can use Direct Memory Access (DMA) </li></ul></ul></ul><ul><ul><li>Accelerated Graphics Port (AGP): Information transfer over 66 MHz </li></ul></ul><ul><ul><ul><li>Designed for video card peripherals </li></ul></ul></ul>
  58. 58. Understanding Hardware: Mainboards and Peripheral Components (continued) Figure 2-1: Mainboard components
  59. 59. Understanding Hardware: Mainboards and Peripheral Components (continued) <ul><li>Other peripherals may have external connections to mainboard </li></ul><ul><ul><li>PS/2 </li></ul></ul><ul><ul><li>COM (Serial) </li></ul></ul><ul><ul><li>LPT </li></ul></ul><ul><ul><li>USB </li></ul></ul><ul><ul><li>IEEE1394 (Firewire) </li></ul></ul><ul><ul><li>PCMCIA </li></ul></ul>
  60. 60. Understanding Hardware: Mainboards and Peripheral Components (continued) <ul><li>Personal Computer Memory Card International Association (PCMCIA) ports: Allow a small card to be inserted into the computer with electronics necessary to provide certain functionality </li></ul><ul><li>Advanced Power Management (APM): BIOS feature that shuts off power to unused peripheral devices </li></ul>
  61. 61. Understanding Hardware: Mainboards and Peripheral Components (continued) <ul><li>Interrupt Request Line (IRQ): Specifies a unique channel from a device to the CPU </li></ul><ul><li>Input/Output (IO) address: Small working area of RAM where CPU can pass information to and receive information from a device </li></ul><ul><li>Plug-and-Play (PnP): OS and peripheral devices that automatically assign the correct IRQ, I/O address, and DMA settings </li></ul>
  62. 62. Understanding Hardware: Video Adapter Cards and Monitors <ul><li>Video adapter cards: Provide graphical display when connected to a monitor </li></ul><ul><ul><li>Commonly referred to as video cards </li></ul></ul><ul><li>Resolution: Total number of pixels that can be displayed on a computer video screen </li></ul><ul><li>Color depth: Total set of colors that can be displayed on a computer video screen </li></ul>
  63. 63. Understanding Hardware: Video Adapter Cards and Monitors (continued) Table 2-3: Memory requirements for screen resolution and color depths
  64. 64. Understanding Hardware: Video Adapter Cards and Monitors (continued) <ul><li>Refresh rate: Rate at which information displayed on a video screen is refreshed </li></ul><ul><ul><li>Measured in Hertz (Hz) </li></ul></ul><ul><ul><li>Two types of refresh rates: </li></ul></ul><ul><ul><ul><li>HSync (horizontal refresh) </li></ul></ul></ul><ul><ul><ul><li>VSync (vertical refresh) </li></ul></ul></ul>
  65. 65. Understanding Hardware: Keyboards and Mice <ul><li>Facilitates user input and direction </li></ul><ul><li>Variety of ways to connect to motherboard </li></ul><ul><ul><li>Serial port </li></ul></ul><ul><ul><li>Large circular AT 5-pin connector </li></ul></ul><ul><ul><li>Small circular PS/2 6-pin connector </li></ul></ul><ul><ul><li>USB connection </li></ul></ul><ul><ul><li>Wireless or radio connection </li></ul></ul><ul><li>Check hardware components against a Hardware Compatibility List (HCL) </li></ul>
  66. 66. Gathering Preinstallation Information Table 2-4: Red Hat 7.2 hardware requirements
  67. 67. Gathering Preinstallation Information (continued) Table 2-5: Sample pre-installation checklist
  68. 68. Gathering Preinstallation Information (continued) Table 2-5 (continued): Sample pre-installation checklist
  69. 69. Gathering Hardware Information <ul><li>Tools and resources to check hardware against a preinstallation checklist: </li></ul><ul><ul><li>Computer manuals </li></ul></ul><ul><ul><li>Windows System Information tool (if Windows already installed) </li></ul></ul><ul><ul><li>Windows Device Manager (if Windows already installed) </li></ul></ul>
  70. 70. Gathering Hardware Information (continued) Figure 2-2: The Windows System Information tool
  71. 71. Gathering Hardware Information (continued) Figure 2-3: The Windows Device Manager
  72. 72. Gathering Hardware Information (continued) Figure 2-4: The Windows Display applet
  73. 73. Gathering Hardware Information (continued) Figure 2-5: System Power-On Self Test (POST)
  74. 74. Gathering Hardware Information (continued) Figure 2-6: BIOS Setup Utility
  75. 75. Gathering Software Information <ul><li>Identifying system network configuration: </li></ul><ul><ul><li>Hostname </li></ul></ul><ul><ul><li>IP address </li></ul></ul><ul><ul><li>Netmask </li></ul></ul><ul><ul><li>Gateway </li></ul></ul><ul><ul><li>DNS servers </li></ul></ul><ul><ul><ul><li>Resolve FQDNs </li></ul></ul></ul>
  76. 76. Gathering Software Information (continued) <ul><li>Dynamic Host Configuration Protocol (DHCP) server: Server on network providing IP configuration to requesting computers </li></ul><ul><ul><li>If selected during installation, Linux will attempt to get IP settings from a DHCP server on the network </li></ul></ul>
  77. 77. Gathering Software Information (continued) Table 2-6: Common Linux packages
  78. 78. Gathering Software Information (continued) Table 2-6 (continued): Common Linux packages