4 The Linux Operating System

		or CD-ROM is run by the computer. (Actually, even this behavior is under software control. The BIOS system, usually stored in read-only memory on the motherboard actually determines the sequence of steps at boot time). Linux installations work by providing the user with a special ''boot floppy" which actually directs the computer to run a minimal Linux system with just enough features to carry out the rest of the procedure. Often, this boot floppy requires a second or third "supplemental floppy" which may contain additional drivers and utilities.

		Once the floppy-based Linux is running, the user answers a series of questions. For Red Hat distributions, one is required to select a language, select a keyboard type, and then select the media on which the remaining components of the distribution should be found. CD-ROM is common, and probably the most reliable. It is also possible to install using data that is stored on a remote NFS mountable file system, or a remote (possibly anonymous) FTP server. Network based installation offers instant gratification and low cost, but can be trickier to debug if something goes wrong.

		4.8.1 Installation by CD or Network?

		More often than not you will install Linux on a single machine from a CD-ROM. When you perform an installation on a network of machines or a Beowulf, it is often more appropriate to do a CD installation on the first machine, and install the rest of the machines across the network from the first, exporting the CD file system via NFS to the other machines. Cloning of nodes in this way is discussed in Section 6.3.

		The simplest way to install Linux from a CD is to FTP installation floppy images from the Internet and the rawrite utility to write the images to floppy disks from DOS. After creating your boot floppies, the installation program will be able to access the files on the CD to install the operating system. Some distributions like Red Hat Linux, are distributed on bootable CDs. Newer computers that are able to boot from a CD-ROM will be able to start the installation process simply by booting from the CD.

		Installation over the network is generally a slower process than CD installation. It requires network card, modem, parallel null modem cable, or other means of network connectivity. It usually does not make sense to attempt an installation over a low bandwidth network. Network installation is most suited for situations where you already have a Linux distribution on a computer on your LAN, and you want to install the distribution on other machines on the same LAN. Network installation requires you to know the IP addresses of the NFS, FTP, or SMB server which is exporting the distribution files to the destination machine. The destination