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Linux Redhat 6.3

Red hat is open source Operation System..

 

An Operating system is a program that manage computer hardware and software for the user. Os systems were originally designed to perform repetitive hardware tasks, which centered around managing files, running programs and receiving commands from the user. You interact with the Os system through user interface, which allows the Os to receive and interpret instructions sent by the user. You only need to send an instructions to the Os to perform a task, such as reading a file or printing a document. An Os user interface can be as simple as entering commands on a line or as complex as selecting menus and icons on a desktop.

An operating system also manages software application. To perform different tasks, such as editing documents or performing calculations, you need specific software applications. An editor is an example of a software application that enables you to edit to document, making changes and adding new tasks. The editor itself is a program consisting of instructions to be executed by the computer. For the program to be used, it must first be loaded into computer memory, and then its instructions are executed. The Os controls the loading and execution all program, including any software applications. When you want to use an editor, simply instruct the Os to load the editor application and execute it.

File management, program management and user instructions are traditional features common to all Os. Linux, like all version of Unix, adds more features. Linux is a multiuser and multitasking. As it s a multitasking system, you can ask the system to perform several tasks at the same time. While one task is being done, you can work an another. For example, you can edit a file while another file is a printed. You do not have to wait for the other file to finish printing before you edit. As it is a multiuser system, several users can log in to the system at the same time, each interacting with the system through his or her own terminal. 

 

Duties of the System Administrator

Installing and configuring servers

Installing and configuring application software

Creating and maintaining user accounts

Backing up and restoring files

Monitoring and tuning performance

Configuring a secure system

Using tools to monitor security

What Is Red Hat Enterprise Linux?

Starting in 2001, Red Hat, Inc. began offering Red Hat Enterprise Linux in addition to their original consumer operating system, Red Hat Linux. In 2003, Red Hat started the Fedora Project to release the Fedora Core operating system instead of Red Hat Linux. The Fedora Project progresses at a rapid rate, releasing a new version of Fedora every four to six months. This allows new technologies to be tested by millions of users, which in turn decreases the amount of time it takes for these technologies to stabilize into production- ready software. Each release of Red Hat Enterprise Linux is based on a Fedora operating system release. The kernel and all of the other software in Red Hat Enterprise Linux are specifically configured and tested for enterprise-level usage.

      Both Red Hat Enterprise Linux and Fedora are based on open source software developed by the open source community, some of whom are members of the Red Hat engineering team. The term open source means that the programming code is freely available to anyone and that anyone can submit code to an existing open source project as long as the code stays open source. New projects or programs can be created based on a different open source project or program. Open source developers live all over the world, and they collaborate on projects every day together. Open source is generally more stable than proprietary software. You can find more information about the Open Source movement at www.opensource.org. Open Source software is protected by public licenses. The most popular public licenses is the GPL General Public Licenses provided by the Free Software Foundation (FSF)

 The Free Software Foundation specifies four freedoms
    * The software must be freely executable for any purpose
    * The source code must be available so that others can study how it works
    * The software must be freely redistributable
    * All are free to modify the software

Feature of Linux

Network protocol, Multiple processor, Multitasking, Internet facility, Portability, Communication, Graphical user interface(X window system), Hardware support, Network server’s, Application support, System security, Multiuser

Linux Distributions

Linux available for download over the net, this is useful if your internet connection is fast. Another way is order the CD-ROMs which saves time, and the installation from CD-ROM is fast/automatic. Various Linux distributions available. Following are important Linux distributions.

Red Hat Linux       www.redhat.com

SuSe  Linux            www.suse.com
Debian Linux
Mandrake Linux
Caldera Linux
Slackware
Fedora Linux
Ubuntu Linux
Turbo Linux
Sun Solaris
Centos linux

 Where I can use Linux?

You can use Linux as Server Os or as stand alone Os on your PC. (But it is best suited for Server.) As a server Os it provides different services/network resources to client. Server Os must be:

l   Stable

l   Robust
l   Secure
l   High Performance

Linux offers all of the above characteristics plus its Open Source and Free OS. So Linux can be used as:

(1) On stand alone workstation/PC for word processing, graphics, software development, internet, e-mail, chatting, small personal database management system etc.
(2) In network environment as:
(A) File and Print or Application Server
Share the data, Connect the expensive device like printer and share it, e-mail within the LAN/intranet etc are some of the application
(B) Linux sever can be connected to Internet, So that PC's on intranet can share the internet/e-mail etc. You can put your web sever that run your web site or transmit the information on the internet

So you can use Linux for:

l   Personal Work 

l   Web Server

 

l   Software Development Workstation

 

l   Workgroup Server

In Data Center for various server activities such as FTP, Telnet, SSH, Web, Mail, Proxy, Proxy Cache Appliance etc
 

What Kernel Is?

Kernel is heart of Linux Os.

It manages resource of Linux Os. Resources means facilities available in Linux. For e.g. Facility to store data, print data on printer, memory, file management etc .

Kernel decides who will use this resource, for how long and when. It runs your programs (or set up to execute binary files).

The kernel acts as an intermediary between the computer hardware and various programs/application/shell.