BASIC INSTALLATION OF LINUX

Materials:
Working complete PC
CentOS 4.7 Server Installation CD-ROM
Student CD-ROM, "Room 6359"
Objectives:
The student will become familiar with the Linux Operating System including:
Complete a basic installation of a typical Linux onto local HDD,
Understand how to prepare a system for the installation,
Understand the choices made during Linux installation,
Be able to choose between the various Linux distributions.
Competency:
The student will learn how to choose a Linux distribution, prepare a typical PC for the installation of the distribution chosen, and proceed through the installation to completion.
     LINUX Distributions

  1. Although it is a little early to start describing low level operating system functionality, one of the major differences between the various distributions of Linux is based on the way it handles startup and specifically where and how it takes its startup configuration information for the loading of device drivers. Fortunately, there are only 2 major families of Linux viewed from this perspective: those that startup using the BSD (a distributor of UNIX) method of initialization and those that use the System V (another classic major version of UNIX) method.

  2. There are fans of both methods (fanatical maniacal warring factions, as a matter of fact), but the BSD method appears to be far more simpler. In the BSD method, all startup configuration files are kept in the "/etc/" directory including the main files named simply "rc" and "rd.local" Any others will have names like "rc.serial" and so on.

  3. The System V, or "SysV" for short, has many subdirectories within the "?etc/" directory including one named "/etc/init.d/" and others like "/etc/rc0.d/", "/etc/rc1.d", etc. An additional startup configuration file found in "/etc/" itself is "rc.sysinit" While the decision is a technical detail, it is important for you to understand that it does exist and that you will have to become familiar with working with both forms of the operating system.

  4. While this distinction is not necessarily the most important consideration on day number one, this is only the beginning of the differences between the distributions of Linux, and some differences will be extremely important to the user. All of the distinctions between the distributions, or "distros" for short, can be categorized as:

    • OS Initialization Method - The difference between the BSD style and the SysV style already mentioned
    • Distributor Customizations - This includes the features has the distributor added on top of the basic Linux foundation such as Redhat which uses RPM's, a clean and simple package management system that allows the user to install packages (i.e. applications) with a single simple command.
    • Mission Specialization - Covers the role of the computer, whether it is to be a server, network workstation, standalone single (home) user, high powered personal computer (i.e. video game platform), etc. Some distros are specifically optimized for a class of roles (i.e. server OS distros.) This does not mean that they cannot be used in another mission, but it can mean that they will likely not perform as well. One can imagine that a distro specifically aimed at server solutions may not be nearly as "user-friendly" as one intended for use on standalone single-user (home PC) based systems.

  5. The distribution chosen for the course is CentOS Version 4.7. This is a distribution optimized for being an "enterprise" server and is maintained by the public, not by a corporate entity like Redhat. CentOS has a robust, simple and lightweight installation which is the primary reason it has been chosen. The second reason it has been chosen is because it is easy to install without the graphical user interface, and in fact many servers are purposely set up completely lacking the GUI because it makes up the vast majority of the size of the OS. When omitted it can reduce the total size of the OS to as little as 10% of the size it would be with the GUI installed.

    6.  Procedures - Pre-Installation

  6. Be sure that the system has the hard drive that the instructor has chosen for the exercise, installed

  7. Enter BIOS and load BIOS setup defaults (press [F5] then [Enter]. One of the main reasons for doing this prior to the installation of any OS is so that, if at a later time the OS must be restored from backups the BIOS settings are assured to be the same as when the OS was first installed. However, there are a few additional changes that should be made in the BIOS. Since these changes will be made, they should be recorded so that they can be duplicated at a later date if necessary. These settings could be written down and stuffed in an envelop that is then taped to the interior of the case for safe keeping.

  8. Use the left and right arrows to select the main menu choices. Choose Advanced and disable the onboard USB 2.0 controller. It has no eternal ports anyway and the drivers may be difficult to obtain. Enter the Chip Configuration submenu and disable both the onboard audio and network interface devices.

  9. Choose the Boot main menu and be sure that the optical drive is the first device in the boot sequence. Disable the full screen logo and the Boot sector virus protection. Insert the CentOS 4.7 installation CD-ROM, press [F10] to save the changes to CMOS and reboot the machine. It will boot to the CD-ROM and begin the OS setup.

    10.  Procedures - OS Installation

  10. At the prompt type in the word "text" (without the quotes!) If you wait, the CD will start the installation automatically anyway.

  11. The first message offers to test the CD, skip this since it will take way too long to be practical. This brings up the "Welcome to CentOS" screen. Select "OK" You can move around the setup screen by using the [tab] key and you "click" buttons with the [enter] key. You can check and uncheck items with the [spacebar]

  12. In the language selection screen, take English and press OK. Remember the language you choose here is mainly just for the setup program but it could also affect the complete installation of the OS as well including help files, documentation and so on, so it is best to keep it English even if you prefer another language since the translations may not be complete or accurate.

  13. For the keyboard selection choose "US" then press OK. This has to do with the way the keyboards are mapped and the scan codes they generate for the keys. Taking the incorrect keyboard may leave it incapable of sending the correct characters to the OS.

  14. The next screen wants to begin partitioning the hard drive for the OS. Like any OS, Linux must define partitions for it to occupy and these partitions will be formatted using its own file system known as NFS - Network File System, or more specifically the partitions are identified as "ext2" or "ext3" (extensions of NFS version 2 or version 3) The Linux installations allow the user to construct a very complex and specific set of partitions for the OS, but for now choose "Autopartitioning." This results in a warning concerning the partition table information on the hard drive. In Linux the hard drive is refered to as "dev/hda" where dev means the physical storage devices and hda means the first hard drive and hdb would be the second one, hdc would be the third one and so on. Press "yes" to the warning.

  15. This brings up the Automatic Partitioning screen. Press OK and another warning appears indicating that all data on dev/hda will be destroyed, press "Yes" This results in a Partitioning Summary indicating how the automatic partitioning has proceeded to partition the hard drive. Press OK.

  16. This brings up the Boot Loader Configuration screen. It is asking which method of launching the OS we would like to use. The choices concern the low level methods the OS will use to launch itself. The MBR 1st stage OS Boot Strap Loader, just written there by the automatic partitioning tool, finds the first physical sector of the active partition, the Volume Boot Record, and loads it into RAM and passes control to it. This one holds the 2nd stage OS Boot Strap Loader and it is this one that has a choice as to what it will look for, load into RAM and pass control to, and so it is this one that we are configuring now. Select "GRUB" which is a large loader program similar in some ways to the Windows one called "ntldr." Press OK.

  17. This results in an additional informational warning screen starting with "A few systems..." but no further configuration is required and so just press OK.

  18. Under "Boot Loader Configuration" indicate that you do not wish to use a password and press OK. Press OK on the next screen as well.

  19. On e the next screen be sure that "MBR" is chosen and press OK.

  20. On the next screen, "Net Configuration for "eth0" make no changes but be sure that both "Configure using DHCP" and "Activate on boot" are already selected, then press OK.

  21. On the next screen you are expected to set up the hostname of the machine. This is vital to proper network functionality of the machine. Linux uses what is called a hostname to identify the machine on the network. Windows operating systems as of Windows 2000 also use a hostname but in the past they used another "friendly name" type for their network nodes called a "NetBIOS name." The two function quite differently and are how a system can be found by its name rather than its IP address. Choose "Manually" and enter the name as "STAx" where x is your stations number. Do not put a space in the hostname. Modern systems can tolerate them, but they can cause problems on the commandline. Note: hostnames are made available globally in the case where the systems join a network whose domain name is registered with the Internet authorities, but duplicate names are not an issue because they reside within the domain. For example, there is a machine whose name is "mailsvr1" in domain1.com and there is also a server named "mailsvr1" in domain2.com. But their FQDN's (Fully Qualified Domain Name) are "mailsvr1.domain1.com" and "mailsvr1.domain2.com" which are unique. Incidentally, almost every registered domain on Earth has a node named "www" hence one directs a web browser to "www.yahoo.com" the web server within the domain.

  22. On the next screen choose, "No firewall" and press OK. This results in a warning about running the OS without a firewall, tell it to proceed anyway.

  23. The next screen is offering you to install "Security Enhanced Linux" which brings strong encryption versions of many common networking functions, amongst other enhancements to the basic OS. Choose "disabled" and press OK.

  24. This language selection screen now directly effects the installation help files documentation and so on. Choose English(USA) then press OK.

  25. On the Time Zone selection screen simply press OK.

  26. On the Root Password assignment screen enter the password carefully as "rootroot" and be sure that the capslock is OFF. Type it the second time to confirm it. Remember that if you forget this password, you will be reinstalling the OS from scratch again, so make sure you set it to something that you will not forget, ever. Press OK.

  27. On the Package Defaults screen, choose "customize" then press OK. On the Package Selection screen, deselect all of the packages then press OK. The next screen warns that the full installation is about to begin, press OK and the process begins. It should take about 10 to 20 minutes with all of the optional packages omitted as we have done.

  28. Once the installation is complete, accept the message and the system will reboot. Upon rebooting you will be presented with a prompt like this one:

    
STA6 login:

  29. Type in the user name you would like to log on to the system as. This would be "root" which is the administrator of the computer with full rights and no restrictions. Then enter the password "rootroot" and the result will be this: 

    
[root@STA6 ~]#_

  30. At this point your introduction to using the Linux command prompt will begin.

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