Group 4

Operating System

LINUX

Operating system

Linux

What is linux?

Linux-is a freely distributed operating system that

behaves like the Unix operating system. Linux was designed specifically for the PC platform and takes advantage of its design to give users comparable performance to high-end UNIX workstations. Many big-name companies have joined the Linux bandwagon such as IBM and Compaq, offering systems pre-installed with Linux. Also, many companies have started Linux packages, such as Red Hat, Corel, and Samba. However, they can only charge for services and documentation packaged with the Linux software. More and more businesses are using Linux as an efficient and more economical way to run their networks.

• Linux is a complete multitasking, multi-user operating system that behaves like UNIX in terms of kernel behavior and peripheral support. Linux has all the features of UNIX and boasts of its open source code and mainly free utilities.

• The Linux kernel was originally developed for the Intel 80386, which was developed with multitasking as one of its features. The kernel is the lowest-level core factor of the operating system. The kernel is the code that controls the interface between user programs and hardware devices, the scheduling of processes to achieve multitasking, and many other aspects of the system.

• The Linux kernel is a monolithic kernel; all the device drivers are part of the kernel proper. Despite the fact that most of Intel's CPUs are used with single-tasking MS-DOS, Linux makes good use of the advanced multitasking features built into the CPU's instruction set. Linux supports demand paging, which means that only the sections of a program that are necessary are read into RAM. Linux also offers support for copy-on-write, a process that if more than one copy of a particular application is loaded, all tasks can share the same memory. When large memory requirements are needed and only small amounts of physical RAM are available, Linux has another feature called swap space

• . Swap space allows pages of memory to be written to a reserved area of a disk and treated as an extension of physical memory. By moving pages between the swap space and RAM, Linux can, in effect, act as if it had much more physical RAM than it does, with the cost of some speed due to the hard drive's slower access. Linux also supports diverse file systems, as well as those compatible with DOS and OS/2. Linux's file system, ext2fs, is intended for best possible use of the disk.

The History of Linux

History Linux is a freely distributable version of UNIX. UNIX

is one of the most popular operating systems for networking worldwide because of its large support base and distribution. Linus Torvalds, who was then a student at the University of Helsinki in Finland, developed Linux in 1991. It was released for free on the Internet and generated the largest software-development phenomena of all time. Because of GNU software (GNU being an acronym for Gnu's Not UNIX) created by the Free Software Foundation, Linux has many utilities to offer. The Free Software Foundation offers royalty-free software to programmers and developers. From the very beginning, Linux has been entwined with GNU software. From 1991, Linux quickly developed on hackers' web pages as the alternative to Windows and the more expensive UNIX systems.

• When Red Hat released its commercial version of Linux packaged with tech support and documentation, the floodgates broke and the majority of the public became aware of Linux and its capabilities. Now more and more new users are willing to try Linux on their personal PCs and business users are willing to use Linux to run their networks. Linux has become the latest phenomenon to hit the PC software market. Linux is a unique operating system in that it is an active participant in the Open Source Software movement. Linux is legally covered by the GNU General Public License, also known as GPL.

• Open Source software is free but is not in the public domain. It is not shareware either. GPL allows people to take free software and distribute their own versions of the software. However, the vendors who sell free software cannot restrict the rights of users who purchase the software. In other words, users who buy GPL software can make copies of it and distribute it free of charge or for a fee. Also, distributors of GPL software must make it clear that the software is covered by the GPL and must provide the complete source code for the software at no cost. Linux embodies the Open Source model. Open source applies to software for which the source code is freely available for anyone to download, alter, and redistribute.

• . Linux is the perfect operating system for hackers because they can freely download newer versions of the Linux kernel or other Linux utilities of the Internet and instantly change its source code to fix any software bugs found. That way, bugs can be fixed in a matter of hours as opposed to days and weeks. Beta testers and code debuggers are unorganized and spread throughout the world, but surprisingly, they have managed to quickly debug Linux software efficiently and cooperate online through the use of the Internet.

Types of LINUX Operating Systems

•RedHat Linux- Lately, RedHat has been making the headlines with it's Linux distribution. It is one of the most popular distributions out there right now, and supports the Intel, Alpha, and SPARC platforms. Many users prefer RedHat Linux because of its ease of use, installation, and live tech support. RedHat Linux primarily comes bundled with the X Windows System, GNOME and KDE desktop environments, as well as the StarOffice suite.

• Linux Mandrake- Yet another rather popular distribution is Linux Mandrake. Similar to RedHat, it also bundles the X Windows System, GNOME, KDE, and StarOffice. What really distances Mandrake from RedHat Linux is its improved ease of use plus a few added extra tools and utilities.

•Corel Linux- Although less popular than something like RedHat, Corel Linux continues to shine with its usability and ease of installation through its Install Express. It comes with only the KDE environment, but also includes WordPerfect for Linux instead of Sun's StarOffice.

•Debian/GNU- Debian/GNU is intended for the more advanced Linux users out there. Although it is more difficult to use than other distributions, Debian/GNU is frequently chosen for web server purposes. Its stability and web adminstration tools are the reason many webmasters rely on Debian/GNU for their server environment.

•Slackware- As one of the first distributions of Linux created, Slackware continues to be fairly popular. It also includes the usual X Window System, GNOME, and KDE. Slackware boasts excellent stability, at the expense of less updated code and more intermediate to advanced user appeal.

• SuSE Linux- If you're looking full feature bundles with your Linux distribution, try SuSE Linux. Originally created by German programmers, this distribution has become quite popular in Europe and is gaining much recognition in the United States. Of course it includes the standard X Windows System, KDE and GNOME environments, but it distances itself from the other offerings by including a huge amount of bundled software. This distribution is also recommended for newer users.

•Caldera Open Linux- Primarily designed for the business and power user, Caldera Linux focuses on internet applications. It includes a full collection of internet connectivity and access tools, and helps anyone take full of advantage of the internet through Linux.

Keep in mind that all of these distributions are very similar to each other, and their software bundles tend to be too. One major consideration that you should make when choosing a distribution is what you plan on using it for, and if you need particular software applications with it. Your best bet is to go and get an actual CD with the distribution, since it makes it much easier to install and run. You can always try to download it for free, but you'll probably end up finding it to be rather time consuming and difficult.

For example, the best distributions for the new user would be RedHat, Mandrake, Corel, and SuSE. A power or internet-oriented user would probably choose something like Caldera, Slackware, or Debian/GNU.

HardwareYou've got a new computer. You've also got all that new,

shiny, top of the line hardware in there. Will Linux run on it the

way you want it to?

•Hard Drive Partioning This is the biggest problem that

many new Linux users may have when they begin installation. Linux requires its own, individual partition, which is difficult to make on various systems. The most common problem is trying to make two partions out of one Windows partition. Unfortunately, there is no easy way to do this but to clear everything off your hard drive and starting from scratch by budgeting a space for Windows and Linux.

• The ideal and easiest way to get Linux on a new partition, and effectively, on your comptuer, is to have a hard drive with two partitions. One of these partitions is a Windows/DOS partition, while the other one must be unused and can be any format. You can just simply change the unused partition to become a Linux partition, and load Linux right onto it.

• If you're stuck with one large partition on your only hard drive, you must reformat and make two partitions. Doing this will result in losing all your data... so make sure you backup everything before you begin. Even if you have extra space on your big Windows partition, you're still out of luck- you must re-partition your hard drive.

• There are some third-party software programs that will let you resize or compress your current partition to free up space for another one. You are probably going to want to backup everything anyways, because you may end up with a hard drive with nothing on it if something goes wrong.

• You should probably use fdisk in DOS to help you make your two (or more) partitions.

• Drivers Having the correct drivers is crucial

to making sure your distribution of Linux runs correctly with your hardware. The new version of the X Windows System, XFree86 4.0 contains many new drivers that will let you run some of the newest hardware on the market. Of course, your manufacturer always has the best set of drivers for you hardware, so it's normally a good idea to check with them first.

SoftwareAlthough software for Linux is developing daily, the support base for software in Linux is still quite small compared to Windows. However, software for Linux

tends to be open-source and free much like the operating system. And although some software may not be as fancy as Windows software, Linux software

does the job, and it does it well. This guide will attempt to go over some basic Unix commands that

will help you navigate around the Linux, and this guide will also review some of the major software in Linux

available for you.

Software on Linux Running software on Linux can be

fun and can be a hassle. There are a ton of programs out for Linux, but the trick is choosing the one right for you. This is a brief overview of some of the more common software.

•LILO- If you have one or more other operating systems installed with Linux, LILO (Linux Loader) is a program that allows you to select which one to load at your computer's startup. Be warned, LILO messes with your Master Boot Record and if you mess with LILO, you could mess up your computer. (Trust me, it happened to me!) However, LILO is generally stable and easy to use. Distributions like Red Hat bundle LILO with their installation.

• Office Suites- Want something like Microsoft Office, except for Linux? There are two major office suites available for Linux at this time. One is Corel's WordPerfect Suite. The other is a lesser known but equally as powerful Sun Microsystems StarOffice. Both allow users access to most of the features Microsoft Office has to offer. However, WordPerfect for Linux and StarOffice are free to download off the Internet. Corel Linux bundles its WordPerfect with its version.

•Text Editors- Emacs Editor is a very popular text editor in the Linux world. There are many benefits to Emacs and it has become a standard for many Linuxers. Emacs is usually loaded with the distribution installation.

• Emulators- Miss your favorite DOS or Windows application? Not to worry. There are plenty of emulators for Linux that allow users to run DOS or Windows files directly on the Linux system. Two popular DOS emulators are Dosemu and xdos. For the Windows emulation, the current project is Wine. Wine is still being developed but its promises are breathtaking. The ability to run Windows applications on Linux is definitely worthwhile and programs will run just as faster, maybe even faster with the Linux environment. Wine is the solution for many Linux users who like Linux but still use several important Windows applications

•X Window System- This is the program that allows graphical interface on the Linux system. X Windows makes it easy to configure your system. Most distributions come with X Windows and install it when they install the Linux kernel. X is easy to use and makes Linux a whole lot friendlier.

• Gaming- The gaming industry is just gaining speed on Linux. Companies like id are beginning to tailor to Linux gamers. Games like Quake 3 are beginning to have Linux versions in addition to Windows and Macintosh versions. However, many best-selling games like Starcraft have to be emulated on the Linux box using Wine.