Open Source Room: Getting Started with RHEL

@ New Feature of RHEL 8:

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RHEL kernel version 4.18.0-X.
RHEL support up to 4PB of memory.
Default display Xorg is replaced by Wayland.
Cockpit is the default Web console tool for server management.(You can manage RHEL graphically on Microsoft operating system, such as running or creating VM, checking the utilization of RAM and processor, viewing and running services, our shell also becomes available on this, due to which we can run any command on linux)
RPM package validation before installation.(This means that inside RHEL 7, when we run the command of RPM to install a package, it used to run the command without checking the package, but in RHEL 8, the package is checked before installing the package. then the command runs)
New package management DNF introduced.
Introduction to Stratis file system.
Crypto policies to increased security.
PHP 7.2 comes with RHEL 8.
Python version 3.6 is the default.
Nginx web server is available as part of application repo.
Virtual data optimizer - Compression,De-duplication.
Ansible 2.8.5
Image builder - customize images from source RPMs.
Iptables is replaced wit Nftables.
Application streams.

@ RHEL 8 Support The Following Architecture:

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@ Red Hat Certification Path:

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UNIX is an influential and Open Source Licensed Software or Operating System. In which there are many users and the facility to do many things simultaneously. That's why it is called Multi user and Multitasking Operating System. This operating system was developed in Bell Laboratories. Which is also called Bell Labs in short.
It was developed by Ken Thompson, Dennis Ritchie and their associate computer scientist in the year 1969. But its first version was released in the year 1971. Today almost many popular Operating Systems like; Linux, Mac Os X, Android, iOS etc. are based on UNIX Operating System. Or it can be said that UNIX Operating System is the mother of all these popular Operating Systems.

@ Charectorstics of UNIX Operating System:

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UNIX Operating System was written in High Level Programming Language. So it is easy to understand and modify it.
UNIX provides the facility of multi-user and multi-tasking.
UNIX Operating System supports Command Line Functionality.
GUI is also seen in UNIX like Windows Operating System.
UNIX Operating System is available with Open Source License.
UNIX Operating System is the mother of many popular operating systems.
UNIX Operating System is written in High Level Language.
Linux Operating System is born from UNIX Operating System.
Apart from Smartphone and Computer, UNIX Operating System is also used in Server and Supercomputer etc.
UNIX is Fast and Secure Operating System.

@ History of UNIX Operating System:

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In the year 1969, Ken Thompson, Dennis Ritchie and their fellow computer scientists started a project to create an operating system at Bell Laboratories. This project was named Multics at that time. Whose full name is Multi-Information Computing System. Then this operating system mostly supported two users.
This operating system was reformed again in the year 1970 under the name of New Project at Bell Laboratories. This time this new project was named Unix. Whose full name is Uniplexed Information Computing System. This Operating System was written in Assembly Language.
Ken Thompson also created a programming language to create this operating system. Which is called B Programming Language. B Programming Language was created in the year 1969 by improving BCPL Programming Language. But there were some flaws in B Programming Language.
Due to which Operating System could not be created from it. But it was kept Open Source. Due to which Dennis Richie started modifying it and created the C Programming Language in the year 1972. C programming language was a good programming language for UNIX. That's why the Unix Project was rewritten in 1973 in C Programming Language. Whose name was changed to UNIX.

Linux:-

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Basic Characteristics of Linux:-

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Architecture of Linux:-

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Hardware Layer:

Kernel:

The kernel acts as an interface between software and hardware.
The kernel decides which process is to be allocated to the processor for execution and which process is to be kept in the main memory for execution.
There is only one kernel in a system. The main purpose of the kernel is to provide communication between software and hardware.
Managing the file system.
Managing computer memory.
Handling interrupts.
Managing devices.
Managing the process.
Scheduling programs running in memory.
Calculating resources among users.
Handling errors.

Shell:-

Shell is a command line interpreter that provides the interface between the user and the kernel. The main function of Shell is to execute commands.
It takes the command from the user as input and executes this command. After executing the command it provides output to the user.
The shell reads the command interpreter and sends requests to execute the program. Therefore shell is also called command interpreter.
Shell is a command line interpreter as well as a programming language. Therefore it is much more powerful than the windows shell.
There are 2 types of Linux shell Graphical Shell & Command Line Shell. Command line shell speed is very high from graphical.
The shell takes commands from the user and executes kernel's functions.
Shell accepts human readable commands from user and converts them into something which kernel can understand.

Utility:

Utility programs that provide the user most of the functionalities of an operating systems

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