Wednesday, June 17, 2009

OFFICE TOOLS - 3

  • What is Linux?

The free Unix workalike created by Linus Torvalds and friends starting about 1991. The pronunciation /li´nuhks/ is preferred because the name ‘Linus’ has an /ee/ sound in Swedish (Linus's family is part of Finland's 6% ethnic-Swedish minority) and Linus considers English short /i/ to be closer to /ee/ than English long /i:/. This may be the most remarkable hacker project in history — an entire clone of Unix for 386, 486 and Pentium micros, distributed for free with sources over the net (ports to Alpha and Sparc and many other machines are also in use).
Linux is what
GNU aimed to be, and it relies on the GNU toolset. But the Free Software Foundation didn't produce the kernel to go with that toolset until 1999, which was too late. Other, similar efforts like FreeBSD and NetBSD have been technically successful but never caught fire the way Linux has; as this is written in 2003, Linux has effectively swallowed all proprietary Unixes except Solaris and is seriously challenging Microsoft. It has already captured 41% of the Internet-server market and over 25% of general business servers.
An earlier version of this entry opined “The secret of Linux's success seems to be that Linus worked much harder early on to keep the development process open and recruit other hackers, creating a snowball effect.” Truer than we knew.

  • Linux Distribution

A Linux distribution (also called GNU/Linux distribution by some vendors and users) is a member of the family of Unix-like software distributions built on top of the Linux kernel. Such distributions (often called distros for short) consist of a large collection of software applications such as word processors, spreadsheets, media players and database applications. The operating system will consist of the Linux kernel and, usually, a set of libraries and utilities from the GNU project, with graphics support from the X Window System. Distributions optimized for size may not contain X, and tend to use more compact alternatives to the GNU utilities such as busybox, uclibc or dietlibc. There are currently over three hundred Linux distributions. Most of those are in active development, constantly being revised and improved.
Because most of the kernel and supporting packages are some combination of
free software and open source, Linux distributions have taken a wide variety of forms — from fully featured desktop and server operating systems to minimal environments (typically for use in embedded systems, or for booting from a floppy disk). Aside from certain custom software (such as installers and configuration tools) a distribution simply refers to a particular assortment of applications installed on top of a set of libraries married with a version of the kernel, such that its "out-of-the-box" capabilities meets most of the needs of its particular end-user base.
One can distinguish between commercially backed distributions, such as
Fedora (Red Hat), openSUSE (Novell), Ubuntu (Canonical Ltd.), and Mandriva Linux and community distributions such as Debian and Gentoo, though there are other distributions that are driven neither by a corporation nor a community; perhaps most famously, Slackware.

  • Preparing to Install Linux

Contents: Minimum Hardware RequirementsCollecting Information About Your SystemPreparing Your Hard Disk


This chapter presents information you need to know and tasks you need to perform before installing Linux. It helps you make certain that your IBM-compatible PC meets the minimum hardware requirements for Linux. It shows you how to document your system configuration so that you can respond to questions presented by the Linux install procedure. Finally, it shows you how to prepare your hard disk for Linux.

Minimum Hardware Requirements
Linux supports a wide range of PC hardware; but not even Linux supports every known device and system. Your PC must meet certain minimum requirements in order to run Linux. The following sections present these minimum requirements; however, for the latest and most complete information, you should check the Debian Project web site at http://www.debian.org/. The Debian web site will also help you determine if Linux supports all the devices installed in your system.


Central Processing Unit (CPU)
Linux does not support the Intel 286 and earlier processors. However, it fully supports the Intel 80386, 80486, Pentium, Pentium Pro, Pentium II, and Pentium III processors. Nevertheless, some users feel that their 80386 Linux systems respond sluggishly, particularly when running X. So, if you want optimum performance, you should install Linux on a PC having an 80486 processor or better.
Linux also supports non-Intel processors such as the Cyrix 6x86 and the AMD K5 and K6. Most Linux users have systems that use Intel chips; if your system uses a non-Intel chip, you may find it more difficult to resolve possible problems.


Motherboard
Linux supports the standard ISA, EISA, PCI, and VESA (VLB) system buses used on most IBM-compatible PCs. Linux recently gained support for IBM's MCA bus, used in IBM's PS/2 series of computers. However, at the time of this writing, Debian GNU/Linux does not yet support the MCA bus. If you have an IBM PS/2, you may be unable to install Debian GNU/Linux (check the Debian Project web site for the latest available information on support for the MCA bus).
Your motherboard should include at least 16 MB of RAM for optimum Linux performance. Some users have managed to coax Linux into working on systems with as little as 4 MB of RAM. However, if your system has less than 16 MB of RAM, you probably won't be pleased with its performance. If you plan to run X, you may wish to install more than 16 MB of RAM - perhaps 64 MB. Although X operates well with 16 MB of RAM, you can open more windows and switch between them more quickly if you have additional memory.
A handful of motherboards presents special problems when installing Linux. Generally, the problem stems from a bad BIOS, for which a fix is often available. Check the Debian Project web site for details.


Drives
An anonymous wag once quipped that one can never be too thin, too rich, or have too much hard disk space. Fortunately, Linux is not too hungry for disk space. To install and use Linux, you should have at least 250 MB of free hard disk space. (The minimum is about 100 MB, but installing Linux on a system with so little disk space will compel you to omit many useful applications and will leave you with little room to work.)
More realistically, if you plan to use your Linux system as a workstation, you should have at least 600 MB of free disk space; if you plan to user your Linux system as a server, you should have at least 1.6 GB (1,600 MB) of free disk space.
For convenient installation using the CD-ROM included with this book, your system should include an IDE or SCSI CD-ROM drive. It's also possible to install Linux from a PCMCIA CD-ROM drive, an FTP site, an NFS server, an SMB shared volume, or a hard drive. Consult the Debian Project web site for details.
Your system should also include a 3.5-inch floppy drive. You'll use the floppy drive to boot your system from a special Linux diskette you create.

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