webpointmorpheus Linux Info
Installation, Advanced Installation, System Use

Intro Hardware Beginning Install Mouse, Keyboard, etc. Installation Type Boot Loader Networking System Language
Root User Software Packages Firstboot Wizard Basic Usage Advanced Installation Boot Disk Creation Documents in this Series

Introduction Top of Page

This document covers installation of the Linux operating system. The topics that are covered in this document are typical to a general stand-alone workstation or server install, and range from the first considerations to more advanced install items. A general outline for installation is listed immediately below, and the more advanced topics are further down in the document.

What is the system hardware? A detailed list will be helpful during installation, and may prevent scrambling or delays during install.
Beginning the installation
Selecting installation and language, keyboard, mouse, and monitor configurations
Choose an installation type - there are several methods to install the OS
Partition the hard disk
Choose, install, and configure a boot loader
Configure networking and firewall options
Determine the system and additional languages, and timezone
Create root user with password
Select installation software packages
Install the software packages
Firstboot wizard - launches automatically after install upon system restart

Hardware Considerations Top of Page

Below is a list of hardware that must be considered before installing the Linux operating system. Visit the computer hardware section for more detailed computer hardware information. Check the Red Hat Hardware Compatibility List (HCL) for supported hardware.

Motherboard type, drivers, BIOS, etc.
Processor type, size, and architecture
Physical memory (RAM) type, bus speed, and size
Hard disk drive size, type, and quantity
Floppy disk drive - is there one present? - more than one?
CD-ROM or DVD-ROM Drive
Video Card
Sound Card
USB drivers, and other peripherals
Printer, scanner, etc.

Beginning the Installation Top of Page

The most popular method if installation is by CD, and is as simple as inserting the (first) installation CD and booting the computer. After the install environment loads, the first screen will present some options. One can choose a text-based install by typing at the command prompt linux text, as well as repair an already installed system by typing linux rescue. In order to continue with a graphical install, press enter. Under certain conditions (incompatible video drivers or hardware) the graphical install may fail. At this point, type in linux nofb to bypass the framebuffer, and continue in graphical mode. If the graphical install fails again, use a text install.

There are several additional Installer Boot Options available when commencing the install - read the dialog when it's presented. Consider that a text based install is faser, and is the default method for hard disk and network installs.

Language, Keyboard, Mouse & Monitor Top of Page

When graphical installation begins, the first choice to be made is the language to be used during install. Next choice is the keyboard configuration, then the mouse configuration. The hardware is typically detected automatically, and verification of the detection is usually all that's required. If the mouse has only 2 buttons, choose 'Emulate 3 Buttons' so that pressing both mouse buttons can simulate a third button. The final choice in this stage is the monitor settings. The monitor is typically detected automatically. If not, be sure to choose the correct horizontal and vertical sync rates to avoid damage to the monitor.

Installation Type Top of Page

At this point, the install process searches the hard drive for previous Red Hat systems, and if found, offers the option to upgrade. A choice can be made to fresh install, even if an older installation is found. When installing, there are 4 general install types that can simplify software package selection:

Personal Desktop - for single, home, or mobile computers.
Workstation - for computers in an office or highly-networked environment.
Server - for computers that will offer services to other computers.
Custom - pick and choose at will.

The install is not limited by any single choice above. Additional software packages can be added or eliminated later, as further options for package selection will be presented again in the installation. It's good to know the amount of available hard disk space - large installs can place up to 7GB of data on the drive.

The installation process will present an interface called Disk Druid that will help partition the hard drive according to system needs. The Linux operating system works from a single large filesystem that has as it's top the / directory. Additional directories, filesystems, partitions, or hard drives are mounted to mountpoints within this directory structure. There's a dedicated document for Filesystem Management and Administration in this series that digs deeper into Linux filesystems. At this point in the installation process, it's important to understand just enough to get the disk partitioned properly to continue with the installation. At a minimum, there will need to be a partition of at least 10GB for the / filesystem. The system can boot from the cd or a floppy, the /boot partition is not necessary. If the /boot partition is included in the initial scheme, allow at least 100MB storage for the kernel, boot loader, etc. Also, it's good to include a swap partition, which should typically be at least as big as the amount of system RAM that is present, preferrably 2-3 times as big. For additional information about filesystem types, see the Filesystem Management and Administration document.

Typical Linux Filesystem Structure
Directory	Directory Definition	Typical Size
/	Root of the operating system file structure. Contains all directories that are not placed elsewhere.	Can vary depending on the installation and other filesystems. Typically more than 10GB.
/boot	Kernel and boot files	50-100MB
/home	User home directories and files	200MB per user, min.
/usr	Commands and utilities for the system	3GB, min.
/usr/local	Additional programs and utilities	4GB, min.
/opt	Additional user software	4GB, min.
/var	Variable data storage, log files, mail and print queue, web root, etc.	2GB, min.
/tmp	Temporary file location.	500MB, min.

The Boot Loader Top of Page

Linux offers two popular boot loaders: LILO (LInux LOader), and GRUB (GRand Unified Boot loader). There are other boot loaders available, but these two are readily available straight out of the box. A boot loader is a program that loads the operating system kernel into memory from the hard disk after the initial computer POST process. Boot loaders can be used to pass parameters to the Linux kernel at boot time, as well as offer a choice of operating systems to boot (dual booting.) In instances where the / or the /boot partition begins after the 1024^th cylinder of the hard disk (about 8GB), a kernel parameter called 32 bit large block addressing (LBA32) may need to be passed at boot time.

The GRUB Boot Loader

GRUB is a more recent boot loader, and tends to be more robust and forgiving than LILO. The GRUB configuration file is located at /boot/grub/grub.conf. GRUB has three sections, which are outlined below.

The GRUB Structure
Directory	Directory Definition	Typical Size
GRUB Stage 1	typically resides on the MBR	points to GRUB Stage 1.5
GRUB Stage 1.5	resides in the /boot/grub directory	loads filesystem support, proceeds to GRUB Stage 2
GRUB Stage 2	resides in the /boot/grub directory	performs boot loader functions, reads /boot/grub/grub.conf, displays graphical boot loader screen

GRUB can be configured by editing the configruation file directly. There is a GRUB configuration entry at /etc/grub.conf, which is a symlink to /boot/grub/grub.conf. GRUB differs from LILO in that it does not need to be reinstalled after editing the configuration file. The GRUB boot loader can be password protected to prevent user intervention in the boot process of the machine. Use the grub-md5-crypt command.

In the grub.conf file, hard drives are enumerated differently from the typical entries as listed in /dev. GRUB identifies hard disks starting the count at 0, and makes no distinction between IDE or SCSI drives. Therefore, the first partition of the first hard drive (regardless of type) would be listed in grub.conf as (hd0,0). GRUB can be edited interactively by entering the grub command. This action invokes the grub shell, with it's own set of internal commands. From within the shell, type help to see a list of the commands and directives. Of note is the fact that GRUB refers to the as the partition that contains the Stage 2 boot loader. If the system does not have a separate filesystem mounted to the /boot directory, the grub> utility sees the GRUB root partition as /boot/grub/grub.conf. If the system does have a separate filesystem mounted to the /boot directory, the grub> utility sees the GRUB root partition as /grub/grub.conf. The grub> utility can be used to boot the system, find files, view hardware configuration, etc.

The LILO Boot Loader

LILO is older than GRUB, and is the traditional Linux boot loader. The configuration file for LILO is typically stored in /etc/lilo.conf . There are many configuration directives that can be passed through LILO, for assistance type man lilo. If LILO fails to load, there may be an error code passed such as those listed:

L: The first part of LILO has failed to load. Try rebooting the machine. A linear configuration directive may be needed in the configuration file.
LI: The second part of LILO has failed to load, or the /boot/boot.b file is incorrect or missing. A linear configuration directive may be needed in the configuration file.
LIL, LIL-, LIL?: LILO has loaded, but cannot operate properly. Try rebooting the machine. A linear configuration directive may be needed in the configuration file.

Configuration parameters can be passed to LILO with a append=parameter line placed in lilo.conf. LILO needs to be reinstalled after editing the configuration file. There is a version of LILO called ELILO that is available for Pentium and Itanium processors. ELILO supports Extensible Firmware Interface.

Network & Firewall Top of Page

The next portion of installation is the configuration of NIC(s) (Network Interface Cards) and the Firewall. NICs are typically detected during the install, and presented in a GUI fashion. A choice is offered as to setting an IP address and Subnet Mask manually, or having one determined via DHCP. There are additional settings for DNS, and the hostname.

The Linux Firewall will block certain network traffic that may be inbound to the system. It is a good idea to configure this facility unless one is already provided on the local network. When checking yes to Firewall configuration, there is a GUI interface provided that allows choices for the services that will be offered by the system.

System Language & Timezone Top of Page

At this point, it's time to choose the system language. The previous language choice was for the install process only. Support for additional languages can be installed, and the correct time zone in which the system will operate can be chosen. It is best to check the box that says 'System clock uses UTC'.

The root User Top of Page

Within the world of Linux, one hears the term root often, and to a person who is new to the territory, the different meanings of the term can be confusing. There are (at least) three meanings for the term root, as listed:

root user: when the term root is applied to a user, it means the all-supreme system-wide holy profile. The power of this account is not to be underestimated, as it typically has full system wide anything-goes privileges. Watch what you do with this account!
root file system: everything in Linux is based upon a hierarchical file structure that has as it's topmost echelon the / directory. This is the root of the filesystem.
root home directory: this is a special home directory (/root where the root user's configuration settings and other high-level files are kept. This directory is separate from the typical user home directories (/home).

When creating the root user account, the password is all that is mandatory to enter. A good strong password is suggested to curtail anyone who would care to attempt to crack the authentication of the root user account.

Software Packages Top of Page

There are lots of software packages to choose from at install time. The array of packages that will be chosen are typically based upon the intended use of the system that is being installed. Something to note is that some software packages are dependent upon other packages. Any dependencies must be resolved before the install will continue. Typically, the install process will give an alert if there are failed dependencies. Depending on which packages are chosen for install, as well as the number chosen, the install process may take a while. Sit back, relax, have a cup of coffee, and enjoy the continually repetitive graphic display.

Firstboot Wizard Top of Page

When the installation process has finished installing all files, it will insist on rebooting. When it reboots, a one-time interactive utility will launch called the Firstboot Wizard. The Firstboot Wizard presents a license agreement, and settings for establishing the system time and date, whether to synchronize time with a time server, etc. Next the GUI launches and prompts for monitor settings. An additional user account can also be created.

At this point, the system will present options that will be addressed based upon the installed services, packages, and intent of the system. If the system is to authenticate users over a network, there will be a dialog box that will present choices. It is possible to authenticate using any of several protocols, as listed below. For added security, it is advised to check the box on the Authentication tab to use Shadow Passwords and MD5 Encryption.

Network Authentication Protocols
Protocol	Definition	Usage
NIS	Network Information System	Used with NFS (Network File System)*
LDAP	Lightweight Directory Access Protocol	LDAP is a networking protocol for querying and modifying directory services running over TCP/IP. LDAP is used in Microsoft Active Directory, among others.
Kerberos		Kerberos allows individuals communicating over an insecure network to prove their identity to one another in a secure manner.
SMB	Server Message Block	Used with SAMBA file share.
Winbind
Hesiod	Leverages DNS	uses DNS functionality to provide access to databases of information to distribute information kept in the `/etc/passwd`, `/etc/group`, and `/etc/printcap` files
*NOTE: NIS works with an older version of access protocol which was Sun Microsystems' "Yellow Pages" (YP) client-server directory service protocol for distributing system configuration data. The key commands are: `ypcat`, `ypmatch`, `ypwhich`, `ypclnt`, `yppasswd`, `ypset`, and `ypmake`. See the MAN pages for details.

Basic System Use Top of Page

Linux is a multi-tasking environment. What this means is that the computer can interact with several users and several processes simultaneously. This concept is important in network servers, as it is virtually impossible to have a production server that can only perform one task at a time. In order to work within the Linux system, the user must login. There are two login options: GUI (Graphical User Interface), or X-Windows, and the BASH shell. The default login (shell type or GUI)can be set in the /etc/inittab file by changing the line id:3:initdefault: to the desired runlevel. There is a help section available called the MAN pages. In a command prompt, type man command to view the MAN page for that command or topic. The MAN pages are stored in a location that is accessible by typing the manpath command. The Linux system must be shut down properly to close all filehandles and stop all services sequentially. There are several commands that will shut the system down: shutdown, halt, and reboot, etc. Check out the command parameters for different shutdown/reboot options.

Linux System Terminal Outline
Name	Shortcut Keys	Type
tty1	Ctrl+Alt+F1	command line type shell
tty2	Ctrl+Alt+F2	command line type shell
tty3	Ctrl+Alt+F3	command line type shell
tty4	Ctrl+Alt+F4	command line type shell
tty5	Ctrl+Alt+F5	command line type shell
tty6	Ctrl+Alt+F6	command line type shell
tty7 (:0)	Ctrl+Alt+F7	graphical

Advanced Installation Topics Top of Page

The installation process may involve advanced configuration for hardware, or an installation method that must be pre-configured itself. This section addresses these and other topics.

SCSI Devices Top of Page

SCSI (Small Computer System Interface) describes a type of hardware connection that permits multiple scalable connections that can perform high rates of data transfer. SCSI devices do not connect directly to the motherboard, they need their own controller card. They are assigned a unique SCSI ID, which is typically set by jumpers on the device itself. There are basically three types of SCSI buses, SCSI narrow, SCSI wide, and SCSI ultra-wide. Depending on the bus, SCSI chains are capable of 7 or 15 devices, and data transfer up to 160MB per second. SCSI controllers can be connected on the ends of the chain, or in the middle of the chain with devices attached on either side of the cable. In either connection configuration, the ends of the ribbon cable must be terminated with a device or a terminator which will suppress data from bouncing from the end of the cable. Read the SCSI document in the hardware section of thie series for more info.

Additional Installation Configuration Top of Page

Listed below are several additional items that may need to be considered during an advanced install. Their definitions and/or a link to more info is included.

IRQ, I/O Addresses, & DMA
Plug-and-Play: typically enabled in the BIOS.
APM & ACPI (Advanced Power Management and Advanced Configuration and Power Interface) - settings for power saving modes.
RAID configuraion - (Redundant Array of Independent Disks)

Advanced Installation Methods Top of Page

CD-ROM type installation is only one method to load Linux onto the box. Although these methods are less common the additional methods include:

Connection to a Windows Samba server
Hypertext Transfer Protocol (HTTP)
File Transfer Protocol (FTP)
Network File System (NFS)
ISO image

These methods will need a working NIC that is configured with drivers from a boot disk of some type - floppy, CD-ROM, or USB.

Automated Installation of Linux Top of Page

Linux installation can be automated with a utility called Kickstart. There are other automated installers, one is FAI (Fully Automated Installation) that works on Debian and other distros. The Linux installation can be performed over a network, installing to several computers at the same time.

Creating a Bootable Disk Top of Page

Stuff happens. Sometimes there is warning and sometimes there is no warning. In the instance when the system won't boot, it's necessary to get into the system somehow and attempt to fix the problem. Boot problems typically come in two flavors: Master Boot Record (MBR) problems - when the entire system fails to load, and filesystem problems - when the boot process commences but fails during that process. Typically the installation CD can be inserted and booted to (may need some additional choices in BIOS) and a rescue attempt can be initiated.

There are essentially three types of boot/rescue disks that can be helpful:

Boot Disk - A bootable disk (floppy, CD-ROM, or USB) that can be booted to, and is capable of pointing to the root file system on the hard drive.
Root/Rescue Disk - Contains a root filesystem that is capable of running the machine. Not necessarily a boot disk.
Utility Disk - A disk with utilites that are capable of repairing the system, such as fsck, mount, vi, etc.

These disks should be available when needed, can be created and customized, and are indispensible in time of need. Read this section for an outline of one Linux boot repair that may become reality. To create a boot disk, consider the following commands:

mkbootdisk --device /dev/fd0 `uname -r`
dd if=/mnt/cdrom/images/cdrom.img of=/dev/fd0

Note that the Linux CD must be the CD-ROM drive and a floppy diskette into the floppy drive, and both must be properly mounted.

Listed below are some additional resources for boot creating and using boot disks:

bootdisk.com - A thorough source of boot info and resources for many systems and platforms.
Redhat Manual Bootdisk HOWTO - Instructions from the source.
Tech Republic - A good article and tutorial.

Installation Problems Top of Page

Hopefully the installation goes through without a hitch. However, this is not always the case. Most installation problems are due to some form of hardware communication, often a driver of some sort. The installation process should place a file in the /root home folder called install.log or install.log.syslog. If this file is present, and the system was able to write to this log during the install process, the problem may be able to be idenfitied.

Other Documents in this Series Top of Page

webpointmorpheus Home Technical Pages Site Map This page was last modified: Friday January 05, 2007 10:09 AM

webpointmorpheus Linux Info Installation, Advanced Installation, System Use

webpointmorpheus Linux Info
Installation, Advanced Installation, System Use