Red Hat Linux Networking , System Administration (P4) ppsx

54 Chapter The screen includes a General Kernel Parameters text field that enables you to enter any special options that Red Hat Linux may need as it boots Your need for special options depends on what hardware you have The remainder of the Boot Loader Configuration screen gives you the option to select the disk partition from which you want to boot the PC A table then lists the Linux partition and any other partitions that may contain another operating system If your system has a Linux partition and a DOS partition (that actually has Windows 95/98 installed on it), the table shows both of these entries Each entry in that table is an operating system that the boot loader can boot After you install the boot loader, whenever your PC boots from the hard disk, the boot loader runs and displays a screen showing the operating systems that you can boot The default selection will be highlighted and will boot automatically after a few seconds You may move the highlight bar to the name of another operating system to boot (The Boot label column in the table in the center section of Figure 3-10 shows the names you may enter at the boot loader prompt.) When booting the PC, if you enter nothing at the boot loader screen, the boot loader waits for a few seconds and boots the default operating system The default operating system is the one with a check mark in the Default column in Figure 3-10 In this case, Red Hat Linux is the default operating system All of the instructions in this section are for your information if you choose to change any of the default settings You can essentially accept the default selections on this screen and click the Next button to proceed to the next configuration step Configuring the Network If the Linux kernel detects a network card, the Red Hat installation program displays the Network Configuration screen (see Figure 3-12), which enables you to configure the LAN parameters for your Linux system This step is not for configuring dial-up networking You need to perform this step if your Linux system is connected to a TCP/IP LAN through an Ethernet card T I P If the Red Hat installation program does not detect your network card and you have a network card installed on the PC, you should restart the installation and type expert at the boot prompt Then you can manually select your network card Standard Installation Figure 3-12 The Network Configuration screen enables you to configure the local area network The Network Configuration screen (see Figure 3-12) displays a list of the network card(s) installed on your system and detected by the Linux kernel The network cards are labeled eth0, eth1, and so on If your system has only one Ethernet card, you see only eth0 Figure 3-12 shows that only one network card has been detected The default selections for the network card are Active on Boot and Configure Using DHCP If you want to enter an IP address manually for your network card or disable the card on boot, click the Edit button to open the Edit Interface dialog box To disable DHCP remove the check mark from the box and enter an IP address and net mask into the appropriate boxes To enable DHCP, click the option to place the check mark there To disable the card on boot, remove the check mark from the box To enable the card on boot, click the option to place the check mark there Normally, you would want your primary Ethernet interface to be configured on system boot 55 56 Chapter The Hostname section of the Network Configuration screen shown in Figure 3-12 lets you choose how your system hostname will be set The choices are: ■■ Automatically via DHCP — This is the default setting Your PC will obtain its IP address and other network information from a DHCP server ■■ Manually — If you choose this option, you must provide a hostname Select DHCP only if a DHCP server is running on your local area network If you choose DHCP, your network configuration is set automatically and you can skip the rest of this section You should leave the Activate on Boot button selected so that the network is configured whenever you boot the system If you have disabled DHCP, you will need to enter the IP address and net mask manually for the network card by editing the card In addition, you have to enter certain parameters for the TCP/IP configuration in the text input fields for hostname and the “Miscellaneous Settings” section shown in Figure 3-12 The Network Configuration screen asks for the following key parameters: ■■ The hostname of your Linux system (for a private LAN, you can assign your own hostname without worrying about conflicting with any other existing systems on the Internet) ■■ IP address of the gateway (the system through which you might go to any outside network) ■■ IP address of the primary name server ■■ IP address of a secondary name server (if available) ■■ IP address of a ternary name server (if available) C R O S S-R E F E R E N C E If you have a private LAN (one that is not directly connected to the Internet), you may use an IP address from a range designated for private use Common IP addresses for private LANs are the addresses in the range 192.168.1.1 through 192.168.1.254 Chapter 11 provides more in-depth information about TCP/IP networking and IP addresses After you enter the requested parameters, click Next to proceed to the next configuration step Configuring the Firewall In this part of the installation process, you can choose the firewall settings for your system security Look at Figure 3-13 as you go through this section’s configuration steps Standard Installation Figure 3-13 The Firewall Configuration screen lets you choose your security level C R O S S-R E F E R E N C E See Chapter 34 for more information about configuring a firewall The first choice that you make from this dialog box is whether you want to enable the firewall or to choose no firewall By default, the installation program selects to enable the firewall for you If you choose to enable the firewall, only connections that are in response to outbound requests are accepted You can also select individual services that are allowed through the firewall You can allow the following services: ■ ■ Remote Login (SSH) — If you allow remote access to your server through the SSH protocol, you should enable this option ■ ■ Web Server (HTTP, HTTPS) — If you plan to run a Web server, you should choose this option You not need to choose this option to use a browser to view Web sites ■ ■ File Transfer (FTP) — If you plan to run an FTP server, you should enable this option You not need to choose this option to retrieve files from FTP sites 57 58 Chapter ■■ Mail Server (SMTP) — If you are going to run an email server, you should enable this option You not need to enable this option to retrieve mail from an ISP If you choose the No Firewall option, all connections are allowed and no security checking is done on your system Select No Firewall only if you have absolute faith in the security of your network T I P Choosing to enable the firewall is always safest, especially if you will be connecting directly to the Internet The final configuration step on the Firewall Configuration dialog box concerns Security-Enhanced Linux (SELinux) SELinux was developed by the National Security Agency (NSA) to provide enhanced security based on access control specified by a security policy You can choose one of three states for SELinux: ■■ Disable — If you select this option, SELinux is not enabled on your system and there is no enforcement of a security policy ■■ Warn — Choosing this option puts a security policy in place, but the policy is not enforced Only warnings about possible security violations are noted If you plan to use SELinux, this option provides a good basis for determining how the security policy would affect the operation of your system ■■ Active — This state applies full enforcement of the SELinux security policy You should choose this option only if you are sure that the policy will not affect your system operation C R O S S-R E F E R E N C E See Chapter 33 for more information about SELinux T I P You can read more about SELinux by visiting the NSA Web site at www.nsa.gov/selinux After you make your configuration choices, click Next to continue Choosing Additional Languages The Additional Language Support screen, shown in Figure 3-14 is where you select the default language to be used on your system Standard Installation Figure 3-14 On the Additional Language Support screen you set the default language for your system as well as additional languages you may use The language you chose to use for system installation earlier in the installation process will be shown as the default language If you desire to use other languages as well, you can select them from the list Select as many other languages as you desire Note that installing additional languages consumes storage space on your disk, so install only the languages you plan to use After you make your selections, click Next to continue Setting the Time Zone After completing the default and additional language selection, you have to select the time zone — the difference between your local time and Greenwich Mean Time (GMT) or UTC (the current time in Greenwich, England), which was selected by the International Telecommunication Union (ITU) as a standard abbreviation for Coordinated Universal Time If you had systems in many different time zones, you might want to choose UTC for all your locations to keep your time synchronized on all your systems The installation program shows you the Time Zone Selection screen (see Figure 3-15) from which you can select the time zone, either in terms of a geographic location or as an offset from UTC Figure 3-16 shows the selection of a time zone 59 60 Chapter Figure 3-15 Select your time zone using the Time Zone Selection screen Notice that there are two tabs on the Time Zone Selection screen: Location and UTC Offset Initially, the screen shows the Location tab, which enables you to pick a time zone by simply clicking your geographic location As you move the mouse over the map, the currently selected location’s name appears in a text field If you want, you can also select your location from a long list of countries and regions If you live on the east coast of the United States, for example, select USA/Eastern Of course, the easiest way is to simply click the eastern United States on the map If the world view of the map is too large for you to select your location, click the View button on top of the map A drop-down list of views appears with several choices Click the appropriate view for your location The other way to set a time zone is to specify the time difference between your local time and UTC Click the UTC Offset tab to select the time zone this way For example, if you live in the eastern part of the United States, select UTC05:00 as the time zone The -05:00 indicates that the eastern part of the U.S is five hours behind UTC time This tab also lets you activate Daylight Savings Time After you select your time zone, click the Next button to proceed to the next configuration step Standard Installation Setting the Root Password After selecting the time zone, the installation program displays the Set Root Password screen (see Figure 3-16) in which you set the root password The root user is the superuser in Linux Because the superuser can anything in the system, you should assign a password that only you can remember, and that others cannot guess easily Typically, make the password at least eight characters long, include a mix of letters and numbers, and (for good measure) throw in some special characters such as + or * Remember that the password is case-sensitive Type the password on the first line, and then reenter the password on the next line Each character in the password appears as an asterisk (*) on the screen for security reasons Both entries must match before the installation program accepts the password The installation program displays a message when it accepts the root password N OT E You must enter the root password before you can proceed with the rest of the installation After you so, click Next to continue with the installation Figure 3-16 Setting the root password 61 62 Chapter Selecting the Package Groups to Install After you complete the key configuration steps, the installation program displays a screen from which you can select the Red Hat Linux package groups that you want to install After you select the package groups and click Next, take a coffee break while the Red Hat installation program formats the disk partitions and copies all selected files to those partitions N OT E If you selected custom installation as your install type, you will see the screen shown in Figure 3-18 If you chose any other installation type, you will see a screen listing the most commonly installed packages for the installation type you chose You can accept the default on that page or you can select Customize software packages to be installed option to pick your own packages, which will then show you the screen in Figure 3-17 C R O S S-R E F E R E N C E Red Hat uses special files called packages to bundle files that make up specific software For example, all configuration files, documentation, and binary files for the Perl programming language come in a Red Hat package You use a special program called Red Hat Package Manager (RPM) to install, uninstall, and get information about packages Chapter 30 shows you how to use RPM For now, just remember that a package group is made up of several Red Hat packages Figure 3-17 shows the Package Group Selection screen with the list of package groups that you can elect to install An icon, a descriptive label, and a radio button for enabling or disabling identify each package group Some of the components are already selected, as indicated by the checked boxes This is the minimal set of packages that Red Hat recommends for installation for the class of installation (Personal Desktop, Workstation, Server, or Custom) you have chosen You can, however, install any or all of the components Scroll up and down the list and click the mouse on an entry to select or deselect that package group T I P In an actual Red Hat Linux installation, you install exactly those package groups that you need Each package group requires specific packages to run The Red Hat installation program automatically checks for any package dependencies and shows you a list of packages that are required but that you have not selected In this case, you should install the required packages Install only those packages that you think you will need immediately after starting the system Installing too many packages could expose your system to security risks You can always add packages later Standard Installation Figure 3-17 GUI screen from which you select the components to install Because each package group is a collection of many different Red Hat packages, the installation program also gives you the option of selecting individual packages If you click the Customize software packages option, which appears on the Personal Desktop, Workstation, and Server package screens and then click Next, the installation program takes you to other screens where you can select individual packages If you are installing Red Hat Enterprise Linux for the first time, you really not need to go down to this level of detail to install specific packages Notice to the right of each group name there are two numbers separated by a slash For instance, next to the X Window System is 37/41 This means that 37 of the 41 packages in this group have been selected for installation To the right of the numbers is a link labeled Details Clicking this link opens a new screen that lists the packages that are in the selected group You can select or deselect packages as desired After you select the groups you want, click Next to continue with the rest of the installation The installation program now presents the About to Install screen, as shown in Figure 3-18 This screen tells you which disks are required for the installation 63 Standard Installation Click the button next to the parameter you wish to change and select the new parameter from the drop-down list When you are satisfied with the settings, click Next to continue to the System User screen, as shown in Figure 3-23 On this screen you need to create a system user The system user is a regular, nonroot user with ordinary, not superuser access rights After you have filled in the appropriate information into the text boxes, click Next to continue to the Additional CDs screen, as shown in Figure 3-24 If you have any additional CDs or documentation disks from Red Hat you can install them by clicking Install and selecting what you want to install Be sure to put the appropriate CD into your CD drive When you are finished, click Next When the Finish Setup screen appears click Finish, and your newly installed system will boot to the GNOME desktop Figure 3-23 You add a system user on the System User screen 69 70 Chapter Figure 3-24 You can install additional programs from Red Hat provided CDs here Summary In this chapter you learned how to install Red Hat Enterprise Linux and Fedora Core You began by examining the hardware on your system and making a list of the components You checked for hardware compatibility by referring to the Red Hat Web site You learned how to partition your hard drive, and you chose the type of system you wanted to install You chose the packages you wanted to install, and you began the process of installing them on your system Finally, you rebooted your system and ran the Firstboot program to finish the installation CHAPTER Kickstart Installation IN THIS CHAPTER ■ ■ ■ ■ Using the Kickstart Configurator Starting the Kickstart Installation As a system administrator, one of your jobs is installing and configuring Red Hat on other computers This could be time-consuming if you have many servers and clients to administer To make your job easier, a program is available that automates the Red Hat installation process This program is called Kickstart With Kickstart you can create and store configuration files for your server or client installations and then use these files to perform your installations and upgrades Installations and upgrades can be done from a local CD-ROM or using NFS, FTP, Hypertext Transfer Protocol (HTTP), or a hard drive If you are installing across the network, you need to have a Dynamic Host Configuration Protocol (DHCP) server for each network segment Using the Kickstart Configurator Fedora Core has a graphical tool, called Kickstart Configurator, that you can use to configure the Kickstart configuration file The Kickstart configuration file is used to give the installation program the answers to the configuration steps that usually require user intervention So by using Kickstart, you can automate the installation process But before you can use the Kickstart Configurator, you need to install it, since it isn’t installed by default 71 72 Chapter Installing the Kickstart Configurator To install the Kickstart Configurator program in GNOME follow these steps From the desktop, choose Desktop ➪ System Settings ➪ Add/Remove Applications to open the Package Management tool dialog box, as shown in Figure 4-1 Scroll down to the System section, and click Details to the right of Administration Tools to open the Administration Tools Package Details dialog box, as shown in Figure 4-2 Click the check box in front of system-config-kickstart Click Close and then Update on the Package Management tool When the Completed System Preparation screen appears, click Continue When prompted, put installation disk one into the CD drive and Click OK When the Update Complete dialog box appears click OK, then click Quit to close the Package Management tool Figure 4-1 The Package Management tool is used to install packages from the installation CDs Kickstart Installation Figure 4-2 The Administration Tools Package details dialog box You are now ready to start the Kickstart Configurator Follow these steps: Choose Applications ➪ System Tools ➪ Kickstart The Kickstart Configurator window shown in Figure 4-3 appears When the Kickstart Configurator window opens, the Basic Configuration dialog box is shown on the right side You will notice that many of the text fields are already filled in This is because the program has loaded the anaconda-ks.cfg file that was created during your system installation N OT E The anaconda-ks.cfg file you see will be based on the type of installation you did You should keep in mind that there may be significant differences between a server configuration file and a workstation or desktop configuration file, although having a file to refer to is always a good place to start 73 74 Chapter Figure 4-3 The Kickstart Configurator program opens to the Basic Configuration dialog box On the left side of the window is a list showing the other configuration dialog boxes Clicking an item in the list will open its respective dialog box on the right side of the Kickstart Configurator window Beginning with the basic configuration, the fields are: ■■ Language — Click the down arrow on the right of the field, and click the language you want to use for the installation ■■ Keyboard — Click the down arrow on the right of the field, and click the language appropriate for your keyboard ■■ Mouse — Click the down arrow on the right of the field, and click the appropriate mouse for your system If you have a two-button mouse and want to emulate a three-button mouse, check the box to emulate three buttons ■■ Time zone — Click the down arrow on the right of the field, and click the appropriate time zone for your location Click the Use UTC Coordinated Universal Time clock check box if you want your time to be set to UTC (Coordinated Universal Time) UTC was previously known as GMT, or Greenwich Mean Time Kickstart Installation ■ ■ Root password — Enter the password for the root user Notice that it will be encrypted by default unless you remove the check from the box ■ ■ Language support — Choose additional languages you want to install on your system by checking the box in front of each language’s name ■ ■ Target architecture — This field lets you choose the type of system on which you are installing For example, choose x86 for a typical Intel Pentium system ■ ■ Reboot system after installation — By default, the system reboots unless you remove the check from the box ■ ■ Perform installation in text mode — By default, the installation is performed in graphical mode unless you remove the check from the box ■ ■ Perform installation in interactive mode — Place a check in this box if you want to use interactive mode during the installation This method still uses the Kickstart configuration file but lets you see the options selected for installation one screen at a time You need to click Next to continue at each screen After you have verified or entered the appropriate information into the Basic Configuration dialog box, click Installation Method to open the Installation Method dialog box shown in Figure 4-4 In the Installation Method dialog box you select whether you want to a new installation or an upgrade of an existing system On the Installation Methods screen, you can pick the type of installation you will be performing You can choose to a new installation or an upgrade by clicking the radio button in front of your choice If you choose to upgrade an existing system you won’t have to define partitions or packages for the installation program to use because the existing partitions and packages will be used N OT E You will require a separate disk for each type of installation You cannot use a disk meant for a new installation to an upgrade, or use a disk meant to upgrade a system to a new installation 75 76 Chapter Figure 4-4 The Installation Method dialog box is where you choose how to perform the installation You can also choose the type of media you will be using for the installation The default choice is CD-ROM You also have the following choices: ■■ NFS — If you choose this method, two additional fields will appear where you need to enter the name of the NFS server and the directory to use ■■ FTP — If you choose this method, four additional fields will appear You need to enter the name of the FTP server and the directory to use in two of the fields You are also given the opportunity to show an FTP username and password by clicking the check box and entering the appropriate information ■■ HTTP — If you choose this method, two additional fields will appear where you need to enter the name of the HTTP server and the directory to use ■■ Hard Drive — If you choose this method, two additional fields will appear where you need to enter the partition of the hard drive and the directory to use When you are satisfied with your choices, click Boot Loader Options to open the Boot Loader dialog box shown in Figure 4-5 Kickstart Installation Figure 4-5 The Kickstart Configurator program window, showing the Boot Loader Options screen Boot Loader Options Screen On this screen, you have several choices related to the system boot loader You can choose to install a boot loader, not to install the boot loader, or to upgrade an existing boot loader Just click the button in front of your choice You can also set a password for the GRUB boot loader as well as encrypt it by clicking the appropriate check box You can choose the location of the boot loader by clicking the radio button in front of either Master Boot Record (MBR) or first sector of boot partition The final field of this screen allows you to pass additional parameters to the kernel if necessary After making your choices, click Partition Information to open the Partition Information dialog box shown in Figure 4-6 77 78 Chapter Figure 4-6 The Kickstart Configurator program window, showing the Partition Information dialog box Partition Information Screen In this dialog box, you can create your disk partitions and set the mount points for your directories By default, the master boot record (MBR) is cleared during installation If you not want to clear the MBR, click the Do not clear MBR radio button Also by default, all existing partitions are removed during the installation If you not want to this, click the radio button in front of your choice You can choose to remove only existing Linux partitions, or you can keep the existing partitions If you are installing on a new hard drive, you will want to keep the default setting of Initialize the disk label If you are installing on a previously used drive and want to keep the existing drive label, check the Do not initialize the disk label radio box The partition window in this dialog box is currently empty, since you haven’t created any partitions yet To create a partition, click the Add button at the bottom of the screen You see a Partition Options dialog box, as shown in Figure 4-7 Kickstart Installation Figure 4-7 The Partition Options dialog box is where you add and configure partitions N OT E If you aren’t sure about setting up the partitions on your system, you can use the setup shown in the anaconda-ks.cfg file as a guide These partitions are the defaults selected during the Fedora Core installation and generally work well The Partition Options dialog box contains the following fields, which you need to fill in: ■ ■ Mount Point shows the place in the file system where the partition will be mounted You can type a mount point or click the down arrow to open the drop-down menu and choose a mount point from the list ■ ■ File System Type is the type of file system you want the partition to be Click the down arrow to open the drop-down menu, and choose the file system type The most common choices here are ext2, ext3, and swap ■ ■ Allowable Drives shows the installed hard drives A check mark in the box means that the drive is available for creating partitions Click to highlight the drive you want to use for the partitions ■ ■ Size (MB) is the field where you can set the size of the partition The default size is 100 MB, but you can set the size to whatever you desire 79 80 Chapter ■■ Additional size options let you set other size restrictions by clicking the radio button in front of the option Fixed size is the default If you choose Grow to maximum of, you need to enter a number in the field to the right of the choice Fill all unused space on disk will use all remaining space on the drive Use recommended swap size is grayed out and not selectable unless the file system type selected is Swap ■■ Force to be a primary partition lets you set the drive as either a primary or logical partition Primary partitions are the first four partitions on the hard drive ■■ Make partition on specific drive lets you choose the hard drive on which to create the partition Just enter the drive identifier; for example, hda would be the first IDE drive ■■ Use an existing partition lets you specify using an already existing partition ■■ Format partition is checked as the default If you not want to format the partition, remove the check mark from the box After you have filled in the fields, click OK to return to the partition information screen You will see the partition information you have chosen displayed in the partition window You can also create software RAID partitions if you desire To create a software RAID partition, click the RAID button at the bottom of the partition information screen You will see the RAID options dialog box, as shown in Figure 4-8 Figure 4-8 The RAID Options dialog box gives you information about creating RAID partitions Kickstart Installation As shown on the RAID Options dialog box, you need to have two software Raid partitions to be able to create a RAID device The only option you have on this dialog box is to accept the option to create a software RAID partition; click Next to continue A Partition Options dialog box like the one shown in Figure 4-7 appears with software RAID already selected as the file system type Enter the remaining options as you when creating a partition earlier Click OK, and the first RAID partition is shown on the partition window Click RAID again, and create another RAID partition After you have created the second RAID partition and have returned to the partition information window, click RAID again Now you have the option of creating a RAID device that has already been selected for you Click OK, and you see the Make RAID Device dialog box shown in Figure 4-9 This dialog box contains the following fields: ■ ■ Mount Point shows the place in the file system where the partition will be mounted You can type a mount point or click the down arrow to open the drop-down menu and choose a mount point from the list ■ ■ File System Type is the type of file system you want the partition to be Click the down arrow to open the drop-down menu, and choose the file system type The most common choices here are ext2, ext3, swap, and vfat ■ ■ RAID Device shows the identifier for the RAID device By default, md0 is selected To change this selection, click the down arrow to the right of the field and select a different identifier Figure 4-9 The Make RAID Device dialog box gives you choices about creating RAID devices 81 82 Chapter ■■ RAID Level is the field where you can choose the RAID level you want to use The choices here are levels 0, 1, and See Chapter for an explanation of RAID levels ■■ RAID Members lets you select the partitions that will be a part of the RAID device In Figure 4-9, the two partitions created previously are shown Click the box in front of the partition to select it ■■ Number of spares lets you specify another partition to use as a spare if you are using RAID level or You need to create an additional software RAID partition for each spare you select ■■ Format RAID device is checked as the default If you not want to format the device, remove the check mark from the box After you have made your selections, click OK to create the RAID device You should now see the device listed on the Partition Information window Click Network Configuration from the list on the left to open the Network Configuration dialog, as shown in Figure 4-10 Figure 4-10 The Network Configuration dialog box is where you configure your network interface card (NIC) Kickstart Installation Network Configuration On this screen, you can configure a network card Click Add Network Device, and you see the Network Device Information dialog box shown in Figure 4-11 In this dialog box, the first network interface card is shown as eth0, and the network type is shown as DHCP DHCP, or Dynamic Host Configuration Protocol, is used to provide an IP address, netmask, gateway address, and a DNS name server address for your system If you are using DHCP on your network, you can accept the defaults for this device If you want to use a static IP address, click the down arrow in the network type field and choose static IP You need to fill in the appropriate network information in the fields at the bottom of the dialog box Another choice shown when you click the down arrow for Network Type is BOOTP BOOTP is a protocol that lets you boot your system across the network For example, if you are planning to set up a terminal server with attached clients, like the Linux Terminal Server Project, you would want to configure BOOTP After you create or modify your NIC settings, click OK to return to the Network Configuration window, and your device is shown in the list If you want to configure additional network interfaces, click Add Network Device and make your choices To make changes to an existing device, click Edit and make your changes as described above Click Authentication from the list on the left to open the Authentication dialog box, as shown in Figure 4-12 Figure 4-11 The Network Device Information dialog box is where you configure your network interface card 83 ... installed on your system and detected by the Linux kernel The network cards are labeled eth 0, eth 1, and so on If your system has only one Ethernet card, you see only eth0 Figure 3-12 shows that only one... the superuser in Linux Because the superuser can anything in the system, you should assign a password that only you can remember, and that others cannot guess easily Typically, make the password... which you can select the Red Hat Linux package groups that you want to install After you select the package groups and click Next, take a coffee break while the Red Hat installation program formats