Basic Linux : Learning from Scratch

Learning Outcomes

• Major three linux distribution families. 
• Common Terms associated with Linux
• Concepts on Linux Kernel

The Linux Foundation is the world's largest open source project started from 1991 AD. It is an umbrella organization of popular companies of networking, embedded system, web tools, cloud computing, automotive, security and blockchain as well. 

Linux is maintained by the network of developers with Linus Torvalds at the head. It borrows heavily from UNIX and file management is similar to UNIX i.e. root at the top. It is fully multitasking, multiuser OS with built-in networking and service processes known as daemons. 

Major Distributions of Linux

Three families 

    a) Debian Family (eg. Ubuntu)

It is pure open source project that aims at providing long term stability and ease of use. Ubuntu is registered trademark of Canonical Ltd. Is uses dpkg based apt package. 

                Debian --> Ubuntu --> Linuxmint 

Ubuntu is built on the top of Debian family and it uses the Unity GUI and differs quite a bit visually from the interface on standard Debians as well as other distributions.  

 

    b) SUSE Family (eg. openSUSE)

   It uses rpm based zypper package and YoST application for sysadmin purposes. It is widely used in retail and other sectors. Like Debian, Ubuntu and Linuxmint, SUSE has, 

    SUSE --> SLES --> openSUSE 

*SLES = SUSE Linux Enterprise Server 

    c) Fedora Family (eg. centOS)

RHEL (Red Hat Enterprise Linux) is the most popular distribution. centOS, virtually identical to RHEL is used for general purpose. It uses rpm based yum package manager. 

Fedora --> RHEL --> centOS, Oracle Linux 

While choosing among Linux system, we will notice the technical difference are mainly about package management system, software version and file location. Once we get a grasp of these difference, it becomes painless to switch between the linux distributions. 

Major Terminologies and their meaning

a) Kernel  : It is the glue between hardware and application. 

b) bootloader : Program that boots the OS (eg. grub, isolinux, etc)

                            boot loader --> linux kernet --> init 

c) service : is a program that runs as a background process 

d) file system : it is a method for storing and organizing files. eg. ext3, ext4, FAT. XFS. etc. 

e) X Windows System : It is a graphical system on nearly all Linux System. 

f) Shell : It is a command line interpreter that interprets the command line input and instructs the OS to perform any necessary tasks and commands. eg. bash, tcsh, zsh, etc. 

Concluding Note: 

The Linux Kernel is the core of a computer OS. A full linux distribution consists of the kernel plus number of other software tools for file, package, etc. Each of these tools provide a small part of complete system. Each tool is often its own separate project with its own developers working to perfect the piece of system. RHEL is based on Linux Kernel 3.10, which is not new but is extremely stable. Various linux distributions have different kernel version. 

Test Yourself