Skip to main content

Introduction to Linux

  Introduction to Linux

 Red hat Enterprise Linux (RHEL)

• Red Hat, Inc. is an American multinational Software

Providing Company

• Open-source software products to the enterprise

community.

• Founded in 1993, Red Hat has its corporate headquarters
in Raleigh, North Carolina.
• Current version is RHEL 8, release on 7th May 2019.

New features in RHEL 8
• Desktop
o GNOME 3 provides a focused working environment that
encourages productivity. A powerful search feature lets you
access all your work from one place. Side-by-side windows
make it easy to view several documents at the same time,
and you can turn off notifications when you need to
concentrate on the task in hand.
o In addition to GNOME 3 and GNOME Classic, Red Hat
Enterprise Linux 7 offers the latest stable version of the
popular KDE desktop.
o File System 
• XFS- RHEL now includes XFS as the default file system,
providing scalability enhancements and additional file
system choice. XFS supports file system sizes up to 500TB.
• Ext4- supports a file system size of 50TB, up from 16TB.
• Btrfs is a relatively young file system especially useful for
local, large-scale use. Btrfs includes basic volume
management, snapshot support, and full data and metadata
checksum integrity and a command-line interface that
makes these advanced features easier to use than in other
large-scale file systems.
• The CIFS networking file system with server message block
(SMB) protocol updates will provide better performance,
security, and more features than were available with
previous protocols. 
• GFS2 commands now more accurately deal with RAID
stripe alignment and placement of critical elements such as
journals and resource groups. This increases the scalability
and performance of GFS2 when the file system is being
created and when it is used.
• Storage
o ISCSI AND FCoE(Fibre Channel over Ethernet) TARGETSThis new implementation strengthens the ability to replace
expensive shared storage arrays with Linux-based storage
appliances built on commodity hardware.
o Dynamic LUN detection- Logical units (LUN) can now be
dynamically recognized by the operating system with no
manual intervention, resulting in fewer reboots and less
downtime.

• Security -
o Dynamic Firewall- The new dynamic firewall service
(firewalld) provides greater flexibility over traditional Linux
iptables enabling the unified management of IPv4, IPv6,
and Ethernet Bridge rule sets. It allows administrators to
quickly respond to new threats by activating new rules
without restarting, thus eliminating service disruptions.
firewall configurations include nearly 50 pre-defined
settings for many commonly used system services.

o Structured Logging- Information stored in the system log
files can now be accessed in a structured form, making
automated log analysis tools more powerful and effective.
o SELinux over NFS- Labeled NFS allows customers to take
advantage of the full power of SELinux and deploy more
secure environments, including secure virtual machine
home directories stored on NFS servers.

• Networking
o Nmcli uses a command-line interface to provide network
administration of local, remote, and headless systems. It
can also be used for network management scripting
purposes. 
o Nmtui is a cursor-based, menu driven text user interface
designed to replace system-config network-tui (in Red Hat
Enterprise Linux 6.)
• Virtualizationo Open VM Tools—bundled open-source virtualization
utilities. 
o 3D graphics drivers for hardware-accelerated OpenGL and
X11 rendering.

Architecture Supports by RHEL
• Red Hat Enterprise Linux 7.x is available as a single kit on
the following architectures: 
o 64-bit AMD
o 64-bit Intel
o IBM POWER7+ and POWER8 (big endian)
o IBM POWER8 (little endian)
o IBM z Systems


RHEL 8 Installation
• Graphical Installation -
o Anaconda, provides a simple graphical method to install
Red Hat Enterprise Linux. Anaconda is different from most
other operating system installation programs due to its
parallel nature. Some screens will be automatically
configured depending on your hardware and the type of
media you used to start the installation. You cannot start the
actual installation process before you finish configuring
these settings.
• Remote installations
o You can use the graphical interface remotely to install Red
Hat Enterprise Linux. For headless systems, Connect
Mode can be used to perform a graphical installation
completely remotely. For systems with a display and
keyboard, but without the capacity to run the graphical
interface, Direct Mode can instead be used to facilitate
setup.
• Automated Installation
o Anaconda installations can be automated through the use
of a Kickstart file. With the help of Kickstart file, we can
perform the automated installation. You can say Kickstart
file is answer file in windows.

Installation Sources
• DVD : You can burn the binary DVD ISO image onto a DVD
and configure the installation program to install packages
from this disk. When using a DVD as an installation source,
make sure the DVD is in the drive when the installation
begins. The Anaconda installation program is not able to
detect media inserted after the installation begins.
• Hard drive : You can place the binary DVD ISO image on
a hard drive and install packages from it. Then, boot the
Anaconda installation program. You can use any type of
hard drive accessible to the installation program, including
USB flash drives. A limitation of using a hard drive as the
installation source is that the binary DVD ISO image on the
hard drive must be on a partition with a file system which
Anaconda can mount.
• Network location : You can copy the binary DVD ISO
image or the installation tree (extracted contents of the
binary DVD ISO image) to a network location accessible
from the installation system and perform the installation
over the network using the following protocols
• NFS : The binary DVD ISO image is placed into a Network
File System (NFS) share.
• HTTPS, HTTP or FTP : The installation tree is placed on a
network location accessible
• Network-based installations can be especially useful when
used together with a TFTP server, which allows you to boot
the installation program from the network as well.

 Minimum Hardware Requirement
• Local media installation (USB, DVD):512 MiB
• NFS network installation:512 MiB
• HTTP, HTTPS, or FTP network installation:1 GiB
• AMD64 and Intel 64 systems, at least two partitions (/ and
swap) must be dedicated to Red Hat Enterprise Linux. To
install Red Hat Enterprise Linux, you must have a minimum
of 10 GiB of space in either unpartitioned disk space or in
partitions which can be deleted.




Comments

Post a Comment

Popular posts from this blog

what is computer network and their types ?

   what is network ? -  A network is a group of two or more computer systems, which are connected together. It also consist of a collection of computers, printers, scanner and other devices that are liked together. Networking has single purpose to share information as fast as possible.   The basic types of network- 1) LAN - LAN stands for Local Area Network. It is used to network computers within a limited area like office, school by using the network media. 2) CAN - Campus Area Network is an interconnection of local area networks within limited geographical area. campus network can be additional to the set of wireless connections. connects several buildings to the same network. Example, corporate office campus, university. 3) MAN - MAN means Metropolitan Area Network, which optimized for a larger geographic area than a LAN, ranging from several blocks of buildings to entire city. 4) WAN - WAN is Wide Area Network that is network connection of wide area such as the w...
Post a Comment
Read more

Levels of Software Testing

   Levels of Software Testing There are various testing levels one of which is unit testing in which the smallest testable part of an application is testing for correctness. In integration testing we check the system when we linking  the various modules.  In system testing we check the system as a whole from customers’ viewpoint. Acceptance testing tries to check whether the system is acceptable by most of the users. Alpha testing is carried out at developer’s site and beta is at customer’s site. A Testers workbench is a virtual environment used to verify the correctness or soundness of a design or model. 11 step testing process is a experience based practical approach for solution to a test assignment.     UNIT TESTING -        Unit testing is a software development process in which the smallest testable parts of an application, called units, are individually and independently scrutinized for proper operation. Unit testing is often...
Post a Comment
Read more

PL / SQL IN DBMS

                                          PL / SQL   Pl/SQL    state Loops in PL/SQL   Built in Function     Cursor Management     Exception INTRODUCTION   PL/SQL stands for Procedural Language/SQL. PL/SQL extends SQL by adding constructs found in procedural languages,  resulting in a structural language that is more powerful than  SQL.PL/SQL is not case sensitive. ‘C’ style comments (/* ……… */)  may be used in PL/SQL programs whenever required.   All PL/SQL programs are made up of blocks, each block performs  a logical action in the program. A PL/SQL block consists of three parts  1. Declaration section   2. Executable section   3. Exception handling section  Only the executable section is required. The other sections are  optional.  A PL/SQL block h...
Post a Comment
Read more