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This article covers how to install elasticsearch in the stable version of Ubuntu 20.04. Now you can use the hosted elasticsearch server for doing searches.

If your application generates a huge amount of data and the search procedures are slow, then using elasticsearch will be best.



This article covers methods to install Nmap on your CentOS machine. Nmap is a handy utility for network scanning and security auditing. Nmap contains variety of options for scanning remote hosts. Have a look at the 15 Mostly Used Nmap Commands for Scanning Remote Hosts.



How to Install Nmap on Debian / Ubuntu ?

1. Install Nmap on Ubuntu by entering the following command:

$ sudo apt-get install nmap

2. The system prompts you to confirm the installation by typing y.

3. After the installation is finished, verify the installed version of Nmap by entering:

$ nmap –version



This article covers how to install Go on CentOS 8. Go language was designed to resolve the common criticisms of other languages while maintaining their positive characteristics and most widely used for writing servers these days.


Run the below command to see the version of the Go language:

$ go version



This article covers the installation of Apache NetBeans on the CentOS system. Here, you will learn the entire procedure for the installation of NetBeans that includes downloading, installation, and launching of NetBeans. At the end, you also learned to uninstall Apache NetBeans if you ever have to do that.

Apache NetBeans is a very powerful Integrated Development Environment (IDE) tool that enables you as a Developer create Desktop, Web and Mobile Applications from its modular framework. It supports Java, PHP, HTML, JavaScript, C, C++, Ajax, JSP, Ruby on Rails and other programming languages using extensions.



This article covers how to install the Wireshark network analyzer tool on CentOS 8 system. Once Wireshark installed on your system, you can capture incoming and outgoing data packets over the network. Wireshark is free & Open source network packet analyzer that is used for network analysis, troubleshooting, etc. Wireshark is a cross-platform software that is available for various Linux/UNIX distributions, Mac-OS, Solaris, BSD & Windows, etc. It uses GTK to implement user interface & captures packets using PCAP. For additional help or useful information, we recommend you to check the official Wireshark website.


To Install package called Whireshark using the dnf command. For a GUI Wireshark application execute:

# dnf install wireshark

To install Wireshark command line tool only execute:

# dnf install wireshark-cli



Features of Wireshark includes:

  • Live packet capture & offline analysis.
  • A number of display filters.
  • Support for hundreds of protocol.
  • Rich VOIP analysis.
  • Read/write feature various file formats.
  • Live data can be read from ethernet port, Bluetooth, USB, Token rings tec.



This article covers how to install the Nginx server on a CentOS machine and add a firewall rule to allow traffic coming towards the Nginx server. Also, we've discussed how to remove Nginx from CentOS.

The Nginx is a free, open source, lightweight and high-performance web server designed for high-traffic use cases. It is also acting as a popular Web server behind the Apache Web server and Microsoft's IIS. Nginx is more resource-friendly than Apache. It can be served in front of other web servers as a reverse proxy.


How to Install Nginx Web Server ?

1. Install the nginx package with:

$ sudo dnf install nginx

2. After the installation is finished, run the following commands to enable and start the server:

$ sudo systemctl enable nginx
$ sudo systemctl start nginx

This will make Nginx start at system boot.



This article covers how to install and manage multiple Java versions on CentOS 7 system. At the end you also learned how to set default Java version. Java is used for developing anything from lightweight mobile to desktop applications.


How to Install Java 8 on CentOS ?

1. Update the system before installing any new programs:

$ yum -y update

2. Install Java 8:

$ yum install java-1.8.0-openjdk

3. Verify Java is Installed

$ java -version



This article covers how to install the Curl command-line tool on CentOS 8 system. Through the curl command, users can download and upload files over the network. curl is a powerful command-line tool for transferring data from or to a remote server. With curl you can download or upload data using various network protocols, such as HTTP, HTTPS, SCP , SFTP , and FTP .


How to Install curl on CentOS ?

Curl package is available in the standard CentOS 8 repositories. 

To install it run the following command:

$ sudo dnf install curl

Once the installation is complete, verify it by typing curl in your terminal:

$ curl



This article covers how to Install phpMyAdmin with Nginx on Ubuntu 18.04 system. When developing a website or web application, many users need the functionality of a database system like MySQL. However, interacting with the system solely from the MySQL command-line client requires familiarity with Structured Query Language — more commonly referred to as SQL — which can present a major hurdle for some users. phpMyAdmin was created to allow users to interact with MySQL through an intuitive web interface, running alongside a PHP development environment. 


How to Secure phpMyAdmin with Let's Encrypt SSL ?

Before starting, you will need to install the Certbot client to download and install Let's Encrypt SSL.

1. First, add the Certbot repository with the following command:

$ add-apt-repository ppa:ahasenack/certbot-tlssni01-1875471

2. Next, update the repository and install the Certbot client using the following command:

$ apt-get update -y
$ apt-get install certbot python3-certbot-nginx -y

3. Once the Certbot has been installed, run the following command to download and install the Let's Encrypt SSL for your domain:

$ certbot --nginx -d phpmyadmin.domain.com



This article covers how to install LAMP stack on CentOS 7. LAMP is a stack of applications that work together on a web server to host a website. With that being said, each individual program serves a different purpose.

In LAMP: 

  • Linux serves as the server's operating system that handles all the commands on the machine.
  • Apache is a web server software that manages HTTP requests to deliver your website's content.
  • MySQL is a relational database management system (RDBMS) whose function is to maintain user's data on a server.
  • PHP is a scripting language for server-side communication.


To install Apache easily using CentOS's package manager, yum:

1. Run the command.

$ sudo yum install httpd

2. Once it installs, you can start Apache on your server.

$ sudo systemctl start httpd.service

3. You can do a spot check right away to verify that everything went as planned by visiting your server's public IP address in your web browser.

http://your_server_IP_address/


Important PHP Modules:

  • php-bcmath.x86_64 : A module for PHP applications for using the bcmath library.
  • php-cli.x86_64 : Command-line interface for PHP.
  • php-common.x86_64 : Common files for PHP.
  • php-dba.x86_64 : A database abstraction layer module for PHP applications.
  • php-devel.x86_64 : Files needed for building PHP extensions.
  • php-embedded.x86_64 : PHP library for embedding in applications.
  • php-enchant.x86_64 : Enchant spelling extension for PHP applications.
  • php-fpm.x86_64 : PHP FastCGI Process Manager.
  • php-gd.x86_64 : A module for PHP applications for using the gd graphics library.



This article covers how to install Skype on your CentOS 7 desktop system. Running Skype on CentOS/Fedora allows you to make Skype calls, group video calls, instant messaging, phone number calls, and screen sharing.


How to Install Skype on CentOS | Fedora ?

The easiest and quickest way to install Skype on Fedora 34/33/32/31/30 is by using the RPM package. 


1. Download the package using wget command:

$ wget https://repo.skype.com/latest/skypeforlinux-64.rpm

2. Install Skype by running the commands:

### On CentOS and Red Hat systems ###
$ sudo yum localinstall skypeforlinux-64.rpm
### On Fedora 22+ systems ###
$ sudo dnf localinstall skypeforlinux-64.rpm

3. Use the following command to launch Skype from the command line and accept terms and conditions for the first time.

$ skypeforlinux



This article covers how to create a new SSH key pair and set up an SSH key-based authentication. You can set up same key to multiple remote hosts on CentOS system. Also, you will learn how to disable SSH password authentication.

SSH, or secure shell, is an encrypted protocol used to administer and communicate with servers. When working with a CentOS server, chances are, you will spend most of your time in a terminal session connected to your server through SSH.

SSH keys are typically configured in an authorized_keys file in . ssh subdirectory in the user's home directory. Typically a system administrator would first create a key using ssh-keygen and then install it as an authorized key on a server using the ssh-copy-id tool.

The public key should be stored in the ~/. ssh/authorized_keys file on the server.


To Create the RSA Key Pair:

1. Execute the command below to create a key pair on the client machine (usually your computer):

$ ssh-keygen

2. Press ENTER to save the key pair into the .ssh/ subdirectory in your home directory, or specify an alternate path.


Best Practices to improve SSH Key Security:

  • Discover all SSH Keys and Bring Under Active Management.
  • Ensure SSH Keys Are Associated With a Single Individual.
  • Enforce Minimal Levels of User Rights Through PoLP.
  • Stay Attentive to SSH Key Rotation.
  • Eliminate Hardcoded SSH Keys.
  • Audit All Privileged Session Activity.



This article covers how to stop and disable FirewallD on your CentOS 7 system. Firewalld is a complete firewall solution that has been made available by default on all CentOS 7 servers. It is highly recommended that you have another firewall protecting your network or server before, or immediately after, disabling firewalld.


How to manage Firewalld ?

1. To disable firewalld, run the following command as root:

$ systemctl disable firewalld

2. To Stop Firewalld, execute the following command as root:

$ systemctl stop firewalld

3. To check the status of firewalld, run the following command as root:

$ systemctl status firewalld



This article covers how to change timezone in CentOS 7. A time zone is basically a region of the globe that observes a uniform standard time for constitutional, business and cultural purposes.

To get detailed information your CentOS server's date, time, and timezone you use the timedatectl command:

$ timedatectl

To Delete the current /etc/localtime file or symlink:

$ sudo rm -rf /etc/localtime



This article covers how to change the hostname on CentOS 7 using different methods. By default, your server is started with the server's given name as the hostname. Some software such as cPanel requires a valid fully qualified domain name (FQDN) for the hostname to be used during their licensing verification system.


To Change a server's hostname:

1. Using a text editor, open the server's /etc/sysconfig/network file. The following example shows how to open this file in the GNU nano text editor:

# sudo nano /etc/sysconfig/network

2. Modify the HOSTNAME= value to match your FQDN hostname, as shown in the following example:

HOSTNAME=myserver.domain.com

3. Open the file at /etc/hosts. To update the information for internal networking, change the host that is associated with the main IP address for your server, as shown in the following example:

127.0.0.1      localhost localhost.localdomain
123.45.67.89   hostname.domain.com   hostname

4. Run the hostname command. This command enables you to change the hostname on the server that the command line remembers, but it does not actively update all of the programs that are running under the old hostname. The following code provides an example:

# hostnamectl set-hostname hostname.domain.com
# hostname
hostname.domain.com
#

5. Use the following command to restart networking on your server to ensure that changes persist on restart:

# /etc/init.d/network restart



This article covers how to change SSH port on your Linux system. SSH (Secure shell) is a cryptographic network protocol used to connect to a remote server securely and it transfer the data in encrypted form between the host and the client.

The default TCP port for SSH is 22, and by changing this default port to the other, it can prevent automated bots and malicious users from being brutally forced into the server.

Before changing the default SSH port number, can check the current port with the below command:

# netstat -ntlp | grep ssh


To change the SSH port:

1. Open the main SSH daemon configuration file /etc/ssh/sshd_config:

# vi /etc/ssh/sshd_config

2. Now search line begins with Port 22 and add hashtag (#) in front of that line. 

3. Then add a new Port line below with the custom port.

Note: Replace the sample port number with the custom port number that needs to be set.

4. Save and exit.


How to Restart the SSH daemon for the changes to take effect ?

Run the below commands to restart the SSH daemon and verify that the port changed:

# systemctl restart sshd
# netstat -ntlp | grep ssh



This article covers how to disable FirewallD and install and iptables on CentOS 7 server. The iptables service stores configuration in /etc/sysconfig/iptables and /etc/sysconfig/ip6tables , while firewalld stores it in various XML files in /usr/lib/firewalld/ and /etc/firewalld/ . 

Note that the /etc/sysconfig/iptables file does not exist as firewalld is installed by default on Red Hat Enterprise Linux.

FirewallD is a complete firewall solution that can be controlled with a command-line utility called firewall-cmd. If you are more comfortable with the Iptables command line syntax, then you can disable FirewallD and go back to the classic iptables setup.


To Install and Use Iptables Linux Firewall:

1. Connect to your server via SSH.

2. Execute the following command one by one: 

$ sudo apt-get update 
$ sudo apt-get install iptables

3. Check the status of your current iptables configuration by running:

$ sudo iptables -L -v


Location of iptables rules on CentOS ?

CentOS 7 uses FirewallD by default. If you would like to manage iptables/ip6tables rules directly without using FirewallD, you may use the old good iptables-services service which will load the iptables/ip6tables rules saved in /etc/sysconfig/iptables and /etc/sysconfig/ip6tables when it is started during boot time.



This article covers how to install and Secure MariaDB on a CentOS 7 server. MariaDB is a fork of MySQL managed by the original MySQL developers. It's designed as a replacement for MySQL, uses some commands that reference mysql, and is the default package on CentOS 7.


To Install MariaDB 5.5 on CentOS 7:

1. Install the MariaDB package using the yum package manager: 

$ sudo yum install mariadb-server

2. Once the installation is complete, start the MariaDB service and enable it to start on boot using the following commands: 

$ sudo systemctl start mariadb 
$ sudo systemctl enable mariadb


To install MariaDB on CentOS 8:

1. Open the terminal application. Another option is to log in using the ssh command:

 ssh user@centos-8-server-ip

2. Install the MariaDB on CentOS 8 by running the command:

$ sudo yum install mariadb-server

3. Secure the MariaDB server in CentOS 8 by running the command:

$ sudo mysql_secure_installation

4. Finally test MariaDB installation by running the command:

$ mysql -u root -p


MariaDB vs MySQL:

Even though MariaDB is a fork of MySQL, these two database management systems are still quite different: 

MariaDB is fully GPL licensed while MySQL takes a dual-license approach.

MariaDB supports a lot of different storage engines. 

In many scenarios, MariaDB offers improved performance.



This article covers how to install PHP 7.3 on Ubuntu 18.04 server. Also, you will learn how to configure PHP with Apache and Nginx web servers. 


How to Install PHP 7.4 on Ubuntu ?

Use the following set of commands to enable PPA for PHP 7.4 in your Ubuntu system and install it. You can use this version for production use also.

$ sudo apt-get install software-properties-common
$ sudo add-apt-repository ppa:ondrej/php
$ sudo apt-get update
$ sudo apt-get install -y php7.4

Now use the following command to check installed php version on your system.

$ php -v 


How to Install PHP 7 Modules ?

You can install the required PHP modules on your system as below command:

$ sudo apt-get install php7.2-mysql php7.2-curl php7.2-json php7.2-cgi php7.2-xsl



This article covers how to install LEMP stack on CentOS 7. LEMP stands for the Linux operating system, with the ENginx web server (which replaces the Apache component of a LAMP stack). The site data is stored in a MySQL-based database, and dynamic content is processed by PHP.

A LEMP software stack is basically a group of open source software that is typically installed together to enable a server to host dynamic websites and web apps.


To install Nginx on CentOS:

1. Add the CentOS 7 EPEL repository, run the following command:

$ sudo yum install epel-release

2. Now that the EPEL repository is installed on your server, install Nginx using the following yum command:

$ sudo yum install nginx

3. Once the installation is finished, start the Nginx service with:

$ sudo systemctl start nginx



This article covers how to install phpMyAdmin with Nginx on CentOS 7 system. phpMyAdmin helps to handle the database administration of MySQL, MariaDB and Drizzle servers over the web. It basically provides the intuitive web interface and supports most of the MySQL features to create and drop databases, create/drop/alter tables, delete/edit/add columns, execute any SQL statement and to manage indexes on columns.


To install phpMyAdmin, run the following commands:

# yum install epel-release
# yum install phpmyadmin


To restart nginx, mariadb and php-fpm services, run the following commands:

# systemctl restart mariadb.service
# systemctl restart nginx.service
# systemctl restart php-fpm.service



This article covers how to Install phpMyAdmin with Apache on CentOS 7 system. phpMyAdmin is a database utility used for managing MySQL databases through a graphical web-based interface. It can be configured to manage a local database (on the same system), or a remote database (over a network).


To Install EPEL Repository:

1. Get access to the EPEL repository – the Extra Packages for Enterprise Linux, by running the command.

$ sudo yum install -y epel-release

2. Once that operation finishes, it's a good idea to refresh and update the EPEL repository.

$ sudo yum –y update


To Install Apache Web Server:

1. Install Apache on CentOS use the command.

$ yum install httpd -y

2. Verify the status of Apache by running with the command.

$ systemctl status httpd


To install PHPMyAdmin on CentOS, enter the command:

$ sudo yum -y install phpmyadmin



This article covers how to use the certbot Let’s Encrypt client to obtain a free SSL certificate and use it with Nginx on CentOS 7. 

Let's Encrypt is a new Certificate Authority (CA) that provides an easy way to obtain and install free TLS/SSL certificates, thereby enabling encrypted HTTPS on web servers. It simplifies the process by providing a software client, Certbot, that attempts to automate most (if not all) of the required steps. 

Currently, the entire process of obtaining and installing a certificate is fully automated on both Apache and Nginx web servers.


To Install the Certbot Let's Encrypt Client:

1. Enable access to the EPEL repository on your server by typing:

$ sudo yum install epel-release

2. Once the repository has been enabled, you can obtain the certbot-nginx package by typing:

$ sudo yum install certbot-nginx


How to Install Nginx on CentOS ?

1. To install Nginx, run the command:

$ sudo yum install nginx

2. Then, start Nginx using systemctl:

$ sudo systemctl start nginx


How to configure firewall on CentOS ?

If you have a firewall enabled, make sure port 80 and 443 are open to incoming traffic.

1. If you have a firewalld firewall running, you can open these ports by typing:

$ sudo firewall-cmd --add-service=http
$ sudo firewall-cmd --add-service=https
$ sudo firewall-cmd --runtime-to-permanent

2. If have an iptables firewall running, the commands you need to run are highly dependent on your current rule set. For a basic rule set, you can add HTTP and HTTPS access by typing:

$ sudo iptables -I INPUT -p tcp -m tcp --dport 80 -j ACCEPT
$ sudo iptables -I INPUT -p tcp -m tcp --dport 443 -j ACCEPT



This article covers how to create an Nginx server block configuration to host multiple website on a single CentOS server.

Server Blocks, often referred to as Nginx virtual host are a feature of the Nginx web server that allows you to host multiple websites on one server.

To Test NGINX configuration file, run the command:

$ sudo nginx --t

If the syntax is OK, the output tells you the test was successful.


To restart your Nginx web server and confirm that it's running as expected:

$ sudo systemctl restart nginx
$ sudo systemctl status Nginx


To Enable HTTPS on Domain Hosted on Nginx:

You may consider encrypting your domain using Lets Encrypt SSL to add a layer of protection and secure traffic to and from the webserver:

$ sudo dnf install certbot python3-certbot-nginx
$ sudo certbot --nginx



This article covers how to Install and configure Nginx on your CentOS 7 server. Now you can deploy your applications and use Nginx as a web or proxy server. 

Nginx is a high performance web server software. It is a much more flexible and lightweight program than Apache HTTP Server.


To Install Nginx Web Server on CentOS 8:

1. Install the nginx package with:

$ sudo dnf install nginx

When prompted, enter y to confirm that you want to install nginx. After that, dnf will install Nginx and any required dependencies to your server.

2. After the installation is finished, run the following commands to enable and start the server:

$ sudo systemctl enable nginx
$ sudo systemctl start nginx

This will make Nginx start at system boot.


To configure Firewall Rules on CentOS for Nginx:

1. Run the following command to permanently enable HTTP connections on port 80:

$ sudo firewall-cmd --permanent --add-service=http

2. To verify that the http firewall service was added correctly, you can run:

$ sudo firewall-cmd --permanent --list-all

3. To apply the changes, you'll need to reload the firewall service:

$ sudo firewall-cmd --reload



This article covers how to install MariaDB on Ubuntu 18.04 server. Also, you will learn how to secure and connect to MariaDB server. MariaDB is an open-source relational database management system, commonly used as an alternative for MySQL as the database portion of the popular LAMP (Linux, Apache, MySQL, PHP/Python/Perl) stack. Basically, It is intended to be a drop-in replacement for MySQL.


How to Install MariaDB ?

1. To install it, update the package index on your server with apt:

$ sudo apt update

2, Then install the package:

$ sudo apt install mariadb-server



This article covers how to secure Apache with Let's Encrypt SSL on CentOS 7 using Certbot client. Also, you will learn how to set up a cronjob for automatic certificate renewal. Basically, A security certificate is critical for securing traffic sent from web browsers to web servers. Let's Encrypt certificate is a free, open and automated certificate authority that you can use to encrypt your site. The certificate expires after every 90 days and auto-renews at absolutely no cost.


To Install Certbot in CentOS 8.

Certbot is a client that automates the installation of the security certificate. It fetches the certificate from Let's encrypt authority and deploys it on your web server without much of a hassle.

1. Before downloading certbot, first, install packages that are necessary for the configuration of an encrypted connection:

$ sudo dnf install mod_ssl openssl

2. Download certbot using the curl command:

$ sudo curl -O https://dl.eff.org/certbot-auto

3. Next, move the certbot file to the /usr/local/bin directory and assign the execute file permissions:

$ sudo mv certbot-auto /usr/local/bin
$ sudo chmod 755 /usr/local/bin/certbot-auto


To Assign the permissions to the Document root of a domain:

$ sudo chown -R apache:apache /var/www/domain.com

For the changes to come into effect, restart the Apache service:

$ sudo systemctl restart httpd



This article covers how to install and secure a MySQL server on a CentOS 7 server. MySQL is one of the most widely used database management systems for websites and server applications.


To start the MySQL server daemon with the following command:

$ sudo systemctl start mysqld

systemctl doesn't display the outcome of all service management commands, so to be sure we succeeded, we'll use the following command:

$ sudo systemctl status mysqld

To configure MySQL, run the following command:

$ sudo mysql_secure_installation

To Current MySQL Version, run the command:

$ mysql -u root -p


Terms used in Managing MySQL User Permissions:

  • SELECT – users can read through the database using the select command.
  • CREATE – they can generate new tables.
  • DROP – allows users to remove tables.
  • DELETE – users can take out rows from tables.
  • INSERT – lets users add in rows into tables.
  • UPDATE – enable them to update the rows.
  • GRANT OPTION – they can grant or remove the privileges of other users.



This article covers method to easily configure Apache virtual hosts. You repeat same procedure for multiple domain.

You can use yum to install Apache through CentOS's default software repositories:

$ sudo yum -y install httpd

Next, enable Apache as a CentOS service so that it will automatically start after a reboot:

$ sudo systemctl enable httpd.service


How to Set Up Local Hosts File ?

If you are on a Mac or Linux computer, edit your local hosts file with administrative privileges by typing:

$ sudo nano /etc/hosts

The details that you need to add are the public IP address of your VPS followed by the domain that you want to use to reach that VPS:

127.0.0.1   localhost
127.0.1.1   guest-desktop
server_ip_address example.com
server_ip_address example2.com

This will direct any requests for example.com and example2.com on our local computer and send them to our server at server_ip_address.



This article covers how to install specific version of PHP 7 on CentOS 7 Linux server. PHP is a programming language often used to automate server tasks. It is part of the LAMP (Linux, Apache, MySQL, PHP) stack, which is a bundle of software used for running internet servers and services. PHP handles dynamic content, database requests, and processing and displaying data.


To Verify PHP Version:

You can Check which version of PHP you are running with the command:

$ php –v


To Install PHP with Apache on CentOS:

1. Start by installing the yum-utils package by entering the following command in a terminal window:

$ sudo yum install yum-utils –y

2. Then, enable the epel-release repository by entering the following:

$ sudo yum install epel-release –y

3. Finally, add the following software repositories that contain the PHP packages:

$ sudo yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm

4. For PHP 7.3, you can enable PHP 7.3. Install the release with the following commands:

$ sudo yum-config-manager ––enable remi–php73
$ sudo yum install php php-common php-opcache php-mcrypt php-cli php-gd php-curl php-mysql –y



This article covers how to install Apache on your CentOS 7 system. You can now ready to start deploying your applications and use Apache as a web server.

Basically, The Apache HTTP server is the most widely-used web server in the world. It provides many powerful features including dynamically loadable modules, robust media support, and extensive integration with other popular software.


To Install Apache on CentOS:

1. Update the local Apache httpd package index to reflect the latest upstream changes:

$ sudo yum update httpd

2. Once the packages are updated, install the Apache package:

$ sudo yum install httpd

3. Enable firewalld's http service with the following command:

$ sudo firewall-cmd --permanent --add-service=http

4. Configure Apache to serve content over HTTPS, you will also want to open up port 443 by enabling the https service:

$ sudo firewall-cmd --permanent --add-service=https

5. Finally, reload the firewall to put these new rules into effect:

$ sudo firewall-cmd --reload



This article covers how to create a user with sudo privileges. You can now log in to your CentOS server with this user account and use sudo to run administrative commands.

Performing server administration as a non-root user is a best practice.

For security, your first task when deploying a CentOS instance is to create a non-root user with sudo access.


How to Add a New User Account on CentOS Linux System ?

1. To Create a new user account with the adduser command:

# adduser example_user

2. Set a strong password for the new user (new_user) with passwd.

# passwd new_user



This article covers how to install WordPress on Ubuntu 20.04 with Nginx HTTP Server and Let's Encrypt wildcard SSL Certificates. WordPress is a free, open-source, and most popular content management system that allows you to create a blog on the Internet.


You can install nginx, MariaDB, PHP and all the required PHP extensions with the following command:

$ apt-get install nginx mariadb-server php php-curl php-mysql php-gd php-intl php-mbstring php-soap php-xml php-xmlrpc php-zip php-fpm -y

Once the LEMP server is installed, start the Nginx and MariaDB service with the following command:

$ systemctl start nginx
$ systemctl start mariadb


Nginx's inbuilt features includes:

  • Nginx is built to work on low memory usage.
  • It can support extremely high concurrency.
  • Is Ipv6 enabled.
  • Supports reverse proxy with efficient caching.
  • Provides an inbuilt load balancer.
  • Supports WebSockets.
  • Optimized handling of index files, static files and provides auto indexing.
  • Is accompanied with FastCGI for efficient caching.



This article covers how to install and configure the Memcached caching server on CentOS 8 system through the command-line tool.

Now, you can easily install and configure the Memcached server on your CentOS 8 system easily. 

Memcached is a free and open-source high-performance in-memory key-value data store.

Typically, it used as a caching system to speed up applications by caching various objects from the results of database calls.


To install memcached on CentOS, perform the following tasks as a user with root privileges:

1. Install memcached and its dependencies:

$ yum -y update
$ yum install -y libevent libevent-devel
$ yum install -y memcached
$ yum install -y php-pecl-memcache

2. Change the memcached configuration setting for CACHESIZE and OPTIONS:

i. Open /etc/sysconfig/memcached in a text editor.

ii. Locate the value for CACHESIZE and change it to at least 1GB. For example

CACHESIZE="1GB"

iii. Locate the value for OPTIONS and change it to localhost or 127.0.0.1

3. Save your changes to memcached and exit the text editor.

4. Restart memcached.

$ service memcached restart

5. Restart your web server.

For Apache:

$ service httpd restart



This article covers how to download, configure, and install Moodle powered by the LAMP stack on RHEL 8.

Moodle is the world’s most popular learning management system for building robust online learning sites.

How to open HTTP and HTTPS for Moodle Learning Platform in CentOS 8 ?
To open HTTP and HTTPS services in the firewall to allow traffic to the NGINX web server, run the commands below:

# firewall-cmd --permanent --zone=public --add-service=http 
# firewall-cmd --permanent --zone=public --add-service=https

# firewall-cmd --reload



This article covers how to install Tig on your Ubuntu 20.04 system and hence interacting with Git all the more efficiently.
However, you can get rid of this utility any time you want by following the uninstallation procedure that we have shared with you in this guide.
Tig is a text-mode interface for git. It mainly serves as a Git repository browser. It can also assist in staging changes for commit at the chunk level.

Features of Tig:
1. Browses the commits in the current branch
2. Displays the commits for one or more specific branches
3. Compares two branches
4. Helps to see the changes for a single file
5. Displays the list of stashes
6. Shows references for branches, tags and remotes

To install tig on Ubuntu:
1. First update the system, run:

# sudo apt update

2. To install tig on ubuntu, run:

# sudo apt install tig


To uninstall tig on Ubuntu:
To completely remove tig from your Ubuntu machine, type;

# sudo apt remove tig -y



This article covers the different methods to perform the installation of NodeJS on the CentOS 8 system.

Now that NodeJS is installed on your CentOS 8 system, you can use it to deploy a NodeJS application on the system.
Node.js is a cross-platform, runtime environment that was built on Chrome's JavaScript. This environment is designed to execute JavaScript code on the server-side.

To check Node version number, run the command:

# node --version



This article covers how to setup an SSH key-based authentication as well how to connect to your Linux server without entering a password.
To set up a passwordless SSH login in Linux all you need to do is to generate a public authentication key and append it to the remote hosts ~/.ssh/authorized_keys file.

To Disable SSH Password Authentication
To add an extra layer of security to your server you can disable the password authentication for SSH.
Before disabling the SSH password authentication make sure you can log in to your server without a password and the user you are logging in with has sudo privileges.
The following steps describe how to configure sudo access:
1. Log into your remote server with SSH keys, either as a user with sudo privileges or root:

# ssh sudo_user@server_ip_address

2. Open the SSH configuration file /etc/ssh/sshd_config, search for the following directives and modify as it follows:

/etc/ssh/sshd_config
PasswordAuthentication no
ChallengeResponseAuthentication no
UsePAM no

3. Once you are done save the file and restart the SSH service.
On Ubuntu or Debian servers, run the following command:

# sudo systemctl restart ssh

On CentOS or Fedora servers, run the following command:

# sudo systemctl restart sshd



This article covers how to install atom editor on CentOS 8 using the command-line application.

Atom is a free and open-source text and source code editor for OS X, Linux, and Windows with support for plug-ins written in Node.js, and embedded Git Control, developed by GitHub

To install latest version of Atom using .rpm package on your CentOS 8 machine:
1. First, go to the Atom official website and download the Atom .rpm package:

# sudo curl -SLo atom.x86_64.rpm  https://atom.io/download/rpm

2. You can now install Atom using dnf command:

# sudo dnf localinstall atom.x86_64.rpm

3. Now that Atom is installed on your CentOS system you can launch it from the command line by typing atom or by clicking on the Atom icon (Applications -> Programming -> Atom).



This article covers how to install the RPM package on the CentOS 8 system.

Now you can easily download, install, update and erase Rpm packages on your CentOS system.
While working in Linux, you may have seen downloadable files with the .rpm extension.
Rpm files are designed to be downloaded and installed independently, outside of a software repository.
RPM Package Manager (RPM) is a free and open-source package management system for installing, uninstalling and managing software packages in Linux.

How to Download RPM Installation File on Linux ?
1. To install wget in CentOS, enter the following in a terminal window:

$ sudo yum install wget

2. To install weget in Fedora, enter the following:

$ sudo dnf install wget

3. Now, you can use the wget command to download the .rpm file you want.

Enter the following:

$ wget http://some_website/sample_file.rpm


To check the .rpm file for dependencies using the following command:

# sudo rpm –qpR sample_file.rpm

The system should list all the dependencies:
i. –q – This option tells RPM to query the file
ii. –p – This option lets you specify the target package to query
iii. –R – This lists the requirements for the package


How to install a .rpm file to your Linux CentOS or Fedora system ?
You can use the yum package manager to install .rpm files.
Enter the following:

# sudo yum localinstall sample_file.rpm

The localinstall option instructions yum to look at your current working directory for the installation file.



This article covers how to install and configure Ansible on Ubuntu 20.04. Ansible is a widely used automation tool in DevOps and used by thousands of developers and sysadmins to configure and deploy applications on servers.

It saves time and minimizes the effort required to handle a multitude of servers in a complex IT infrastructure. 


To install Ansible on Ubuntu:

1. First, refresh your system’s package index with:

# sudo apt update

2. Following this update, you can install the Ansible software with:

$ sudo apt install ansible

Press Y when prompted to confirm installation.


To check if Ansible is able to connect to these servers and run commands via SSH:

From your local machine or Ansible control node, run:

$ ansible all -m ping -u root

This command will use Ansible's built-in ping module to run a connectivity test on all nodes from your default inventory, connecting as root.

The ping module will test:

i. if hosts are accessible;

ii. if you have valid SSH credentials;

iii. if hosts are able to run Ansible modules using Python.



This article covers the installation of the LAMP stack (i.e., Linux, Apache, MariaDB, and PHP) on RHEL 8.

LAMP stands for Linux, Apache, MariaDB/MySQL and PHP, all of which are open source.


With the yum commands below, install LAMP stack:

# Will automatically update

$ sudo yum -y update

# Will automatically install Apache/HTTPD

$ sudo yum -y install httpd


To Install MariaDB Database Server on CentOS 8/RHEL 8:

1. Enter the following command to install MariaDB on CentOS 8/RHEL 8.

# dnf install mariadb-server mariadb -y

2. After it's installed, we need to start it.

# systemctl start mariadb

3. Enable auto start at system boot time.

# systemctl enable mariadb

4. Check status:

# systemctl status mariadb



This article covers how to install Apache OpenOffice on CentOS 8. Apache OpenOffice is a software bundle which contains various software tools like word processor, spreadsheet, database management, and so on. It is very much similar to other popular editors like Libreoffice and NeoOffice. 


Main features and tools provided by OpenOffice:

1. Writer a word processor you can use for anything from writing a quick letter to producing an entire book.

2. Calc a powerful spreadsheet with all the tools you need to calculate, analyze, and present your data in numerical reports or sizzling graphics.

3. Impress the fastest, most powerful way to create effective multimedia presentations.

4. Draw lets you produce everything from simple diagrams to dynamic 3D illustrations.

5. Base lets you manipulate databases seamlessly. Create and modify tables, forms, queries, and reports, all from within Apache OpenOffice.

6. Math lets you create mathematical equations with a graphic user interface or by directly typing your formulas into the equation editor.



This article covers MongoDB installation on CentOS 8 system.

Instead, it uses JSON-like documents with dynamic schemas, meaning that, unlike relational databases, MongoDB does not require a predefined schema before you add data to a database. 

You can alter the schema at any time and as often as is necessary without having to set up a new database with an updated schema.


How to Start the MongoDB Service and Test the Database on Ubuntu?

1. Run the following systemctl command to start the MongoDB service:

# sudo systemctl start mongod

2. Then check the service's status:

# sudo systemctl status mongod

This command will return output like the following, indicating that the service is up and running

3. After confirming that the service is running as expected, enable the MongoDB service to start up at boot:

# sudo systemctl enable mongod


How to Managing the MongoDB Service on Ubuntu?

1. The systemctl status command checks the status of the MongoDB service:

# sudo systemctl status mongod

2. You can stop the service anytime by typing:

# sudo systemctl stop mongod

3. To start the service when it’s stopped, run:

# sudo systemctl start mongod

4. You can also restart the server when it’s already running:

# sudo systemctl restart mongod

5. If you ever wish to disable this automatic startup, type:

# sudo systemctl disable mongod

6. Then to re-enable it to start up at boot, run the enable command again:

# sudo systemctl enable mongod



This article covers how to perform Docker installation and Configuration. Also, you will learn how to install Docker CE on the CentOS 8 system. Docker container technology allows you to run applications in a specific and isolated environment.

Docker Community Edition (CE) is the new name for the free Docker product.

To Install Docker CE on Linux:
1. Remove all existing docker applications (that might currently be installed) in order to make sure we are using a clean installation.:

# yum remove docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine

2. Add an external repository that will help us obtain the Docker software:

# dnf config-manager --add-repo=https://download.docker.com/linux/centos/docker-ce.repo

3. Check what versions of docker we have in the repository:

# dnf list docker-ce

4. Install the version that best matches our CentOS server version:

# dnf install docker-ce --nobest

5. We can double-check if the installation was successful by using the version command:

# docker -v



This article covers how to install and configure Netdata on Ubuntu 20.04 LTS and different metrics visualized in it. Netdata provides an excellent solution for monitoring your single node in real-time. You can configure alarms and notifications which can be triggered when a certain event or threshold is exceeded.


To install Netdata on Ubuntu:

1. You can install netdata on Ubuntu by running the following commands.

$ sudo apt update 
$ sudo apt install netdata 

Press 'y' if confirmation prompted by the installer.

2. Edit netdata configuration file in your favorite text editor.

$ sudo vim /etc/netdata/netdata.conf 

3. After modifying its configuration file, you can Save your file and restart netdata service:

$ sudo systemctl restart netdata 



This article covers LibreOffice installation on CentOS 8 distribution. LibreOffice is a powerful and open-source office suite that can be used on Linux, Mac as well as on Windows.

It provides various features such as word documentation, spreadsheets, data processing, drawing, presentation design, Math calculation, and more.


How to uninstall Old LibreOffice or OpenOffice Versions ?

If any previously installed LibreOffice or OpenOffice versions you have, remove it using following command.

# yum remove openoffice* libreoffice* [on RedHat based Systems]
$ sudo apt-get remove openoffice* libreoffice*	[On Debian based Systems]



This article covers the complete installation guide of VirtualBox on the CentOS 8 system.

Oracle VirtualBox is a virtualization software solution that allows you to create and run virtual machines on a single hardware machine.

With VirtualBox, your existing operating system stays unaffected by the virtual environment.


To Start VirtualBox on Linux:

Use the command:

$ VirtualBox

The VirtualBox manager interface will prompt you.

Alternatively, you can use the graphical interface and access the application:

Application >> System Tools >> Oracle VM VirtualBox



This article covers how to flush the DNS cache on Ubuntu. If the sites are not loading properly or you are receiving outdated sites, try to flush the DNS cache to see if the issue resolves. 

Remember, after the DNS cache is flushed, sites will first load slightly slower. 

But once the DNS cache is re-populated, sites will be loaded faster.


Facts about flushing DNS cache on Ubuntu:

1. DNS cache is a temporary database that stores information about previous DNS lookups. 

2. Whenever you visit a website, your OS and web browser will keep a record for the domain and the corresponding IP address. 

3. Flushing DNS cache eliminates the need for repetitive queries to the remote DNS servers and allows your OS or browser to resolve the website's URL quickly.


How to use dns-clean to flush DNS-Cache ?

You can clear the DNS cache is by starting the dns-clean utility. Run the following command in your Terminal to do so:

$ sudo /etc/init.d/dns-clean start



This article covers how to install XAMPP on your CentOS system. XAMPP is an easy to install and use Apache distribution packaged with MariaDB, PHP, and Perl.

XAMPP was first developed by a project team called Apache Friends. As an open-source Apache distribution of a PHP development environment, it consists of cross-platform software (X): Apache (A), MariaDB (M), PHP (P) and Perl (P). 


To install XAMPP on CentOS 8 Linux system:

1. Update system

Ensure your CentOS system is updated.

$ sudo dnf -y update
$ sudo dnf -y install libnsl

2. Download XAMPP on CentOS 8

Install wget on CentOS 8:

$ sudo dnf -y install wget

Download XAMPP installer. Choose the installer matching the PHP version you want to have.

### PHP 8.0 ###

$ wget https://www.apachefriends.org/xampp-files/8.0.1/xampp-linux-x64-8.0.1-0-installer.run

### PHP 7.4 ###

$ wget https://www.apachefriends.org/xampp-files/7.4.14/xampp-linux-x64-7.4.14-0-installer.run

### PHP 7.3 ###

$ wget https://www.apachefriends.org/xampp-files/7.3.26/xampp-linux-x64-7.3.26-0-installer.run

3. The binary installer should be executable.

### PHP 8.0 ###

$ chmod a+x xampp-linux-x64-8.0.1-0-installer.run

### PHP 7.4 ###

$ chmod a+x xampp-linux-x64-7.4.14-0-installer.run

### PHP 7.3 ###

$ chmod a+x xampp-linux-x64-7.3.26-0-installer.run

4. Then run the XAMP installer:

### PHP 8.0 ###

$ sudo ./xampp-linux-x64-8.0.1-0-installer.run

### PHP 7.4 ###

$ sudo ./xampp-linux-x64-7.4.14-0-installer.run

### PHP 7.3 ###

$ sudo ./xampp-linux-x64-7.3.26-0-installer.run


How to Start and use XAMPP on CentOS 8:

XAMPP is installed to /opt/lampp/. To start XAMPP services, run:

$ sudo /opt/lampp/lampp start

To verify installation of XAMPP on CentOS 8 visit the Apache web page:

http://localhost


Stopping and Uninstalling XAMPP on CentOS 8:

To stop XAMPP services run:

$ sudo /opt/lampp/lampp stop

To uninstall XAMPP on CentOS 8, run:

$ cd /opt/lampp
$ sudo ./uninstall
$ sudo rm-rf /opt/lampp



This article covers how you can install Memcached on Ubuntu 20.04. Memcached has proved to be a very reliable caching system since its inception in 2003 and continues to be a favorite among developers in speeding up web applications. 

Memcached is a high-performance, distributed memory object caching server. It is free and open source software intended for use in speeding up dynamic web applications by mitigating database load.


To install and configure memcached on Ubuntu:

1. Update your Ubuntu server:

$ sudo apt update
$ sudo apt upgrade

2. Install memcached server on Ubuntu:

Run apt command as follows:

$ sudo apt install memcached

3. Configure memcached server:

Edit config file named /etc/memcached.conf using a text editor such as nano command or vim command:

$ sudo nano /etc/memcached.conf

OR

$ sudo vi /etc/memcached.conf


How to restart, stop, reload memcached server on Ubuntu:

To Stop service - $ sudo systemctl stop memcached

To start Service - $ sudo systemctl start memcached

To restart Service - $ sudo systemctl restart memcached

To check the status - $ sudo systemctl status memcached



This article covers method to Install and Use Firewalld in CentOS in order to increase the security of your Linux system. Note that the host-based firewall like firewalld is recommended by compliances like PCI DSS. 

FirewallD is a complete firewall solution that manages the system's iptables rules and provides a D-Bus interface for operating on them. Starting with CentOS 7, FirewallD replaces iptables as the default firewall management tool.

Firewalld services are predefined rules that apply within a zone and define the necessary settings to allow incoming traffic for a specific service.


How to install Firewalld on CentOS?

Firewalld is installed by default on CentOS 7, but if it is not installed on your system, you can install the package by running the command:

$ sudo yum install firewalld

Firewalld service is disabled by default. You can check the firewall status with:

$ sudo firewall-cmd --state

If you just installed or never activated before, the command will print not running. Otherwise, you will see running.

To start the FirewallD service and enable it on boot type:

$ sudo systemctl start firewalld
$ sudo systemctl enable firewalld


To open HTTP and HTTPS ports add permanent service rules to the dmz zone:

$ sudo firewall-cmd --permanent --zone=dmz --add-service=http
$ sudo firewall-cmd --permanent --zone=dmz --add-service=https

Make the changes effective immediately by reloading the firewall:

$ sudo firewall-cmd --reload

Zones provided by FirewallD:

1. drop: All incoming connections are dropped without any notification. Only outgoing connections are allowed.

2. block: All incoming connections are rejected with an icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited for IPv6n. Only outgoing connections are allowed.

3. public: For use in untrusted public areas. You do not trust other computers on the network, but you can allow selected incoming connections.

4. external: For use on external networks with NAT masquerading enabled when your system acts as a gateway or router. Only selected incoming connections are allowed.

5. internal: For use on internal networks when your system acts as a gateway or router. Other systems on the network are generally trusted. Only selected incoming connections are allowed.

6. dmz: Used for computers located in your demilitarized zone that have limited access to the rest of your network. Only selected incoming connections are allowed.

7. work: Used for work machines. Other computers on the network are generally trusted. Only selected incoming connections are allowed.

8. home: Used for home machines. Other computers on the network are generally trusted. Only selected incoming connections are allowed.

9. trusted: All network connections are accepted. Trust all of the computers in the network.



This article covers how to install TeamViewer on the CentOS system. Additionally, you will learn how to install, launch, and update TeamViewer on CentOS.

We have also covered how to uninstall TeamViewer in case you no longer need it on your system. 

For some more help regarding TeamViewer, run teamviewer help in Terminal.

TeamViewer is a Robust cross-platform solution that provides secure remote access, remote control, and remote support solution across devices. 

The data traffic between devices are encrypted which makes the TeamViewer very secure. 

This software is available for “Linux, Windows, Mac, Chrome OS” and even for mobile devices like "iOS, Android, and so on".


To Install TeamViewer on CentOS 8:

1. Enable EPEL Repo on CentOS 8

You can install EPEL repo using the below command. This command will enable the repo if it is not already installed:

$ sudo yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm -y

2. Now you can proceed further to install TeamViewer on CentOS 8:

$ sudo yum install teamviewer.x86_64.rpm -y

3. Once the package is installed you can start using team viewer:

$ teamviewer



This article covers how to install skype on the CentOS 8 system. One is using the RPM skype repository and another one is through the snap tool. 

Running Skype on CentOS/Fedora allows you to make Skype calls, group video calls, instant messaging, phone number calls, and screen sharing.


To Install Skype on CentOS:

1. Execute the command;

$ sudo yum localinstall skypeforlinux-64.rpm

2. Press y when prompted to confirm installation.


To Launch Skype on CentOS:

After successful installation, search Skype on your Desktop Environment search bar.



This article covers how to install Apache web server on CentOS 8 distribution. With Apache we server, you can host web pages over the network. Apache is available within CentOS's default software repositories, which means you can install it with the dnf package manager.


To install Apache on CentOS:

1. Execute the command below to install the Apache package:

$ sudo dnf install httpd

After confirming the installation, dnf will install Apache and all required dependencies.

2. If you also plan to configure Apache to serve content over HTTPS, you will also want to open up port 443 by enabling the https service:

$ sudo firewall-cmd --permanent --add-service=https

3. Next, reload the firewall to put these new rules into effect:

$ sudo firewall-cmd --reload

After the firewall reloads, you are ready to start the service and check the web server.


To check your Apache Web Server:

1. Apache does not automatically start on CentOS once the installation completes, so you will need to start the Apache process manually:

$ sudo systemctl start httpd

2. Verify that the service is running with the following command:

$ sudo systemctl status httpd

You will receive an active status when the service is running.


To manage the Apache Process on CentOS:

Now that the service is installed and running, you can now use different systemctl commands to manage the service.

1. To stop your web server, type:

$ sudo systemctl stop httpd

2. To start the web server when it is stopped, type:

$ sudo systemctl start httpd

3. To stop and then start the service again, type:

$ sudo systemctl restart httpd

4. If you are simply making configuration changes, Apache can often reload without dropping connections. To do this, use this command:

$ sudo systemctl reload httpd

5. By default, Apache is configured to start automatically when the server boots. If this is not what you want, disable this behavior by typing:

$ sudo systemctl disable httpd

6. To re-enable the service to start up at boot, type:

$ sudo systemctl enable httpd

Apache will now start automatically when the server boots again.



This article covers how to assign multiple IP addresses to a single interface in Mint OS. By following our guide carefully, you can either assign the IP address temporarily or permanently to your network interface.

NIC stands for network interface controller or network interface (controller) card. WNIC is wireless network interface controller or wireless network interface (controller) card. IP Addresses belong to network interfaces, not to the computer itself.


To Restart network service using command:

# systemctl restart network

To Verify the new IP address using command:

# ip addr


How configure multiple IP address in CentOS ?

Now, in order to add additional IP addresses you'll need to edit the configuration file (from hereon called “config file”) for this specific interface. On CentOS 7, the interface config files are located in /etc/sysconfig/network-scripts/ and they are all prefixed with ifcfg-.


How remove secondary IP address Linux?

To add or remove additional IP adresses and keep the configuration persistent, we need to Edit the corresponding /etc/sysconfig/network-scripts/ifcfg-eth[x] configuration file and add/remove as many additional IPADDR[n] and PREFIX[n] entries as additional IP addresses are required.


To configure a static IP address on CentOS  / RHEL :

1. Create a file named /etc/sysconfig/network-scripts/ifcfg-eth0 as follows:

DEVICE=eth0.

BOOTPROTO=none.

ONBOOT=yes.

PREFIX=24.

IPADDR=your_ip_address

2. Restart network service: systemctl restart network.


How do I login as a different user in Linux?

To change to a different user and create a session as if the other user had logged in from a command prompt, type "su -" followed by a space and the target user's username. Type the target user's password when prompted.


What is Nmcli in Linux?

nmcli is a command-line tool which is used for controlling NetworkManager. nmcli commnad can also be used to display network device status, create, edit, activate/deactivate, and delete network connections. Typical Uses: Scripts: Instead of manually managing the network connections it utilize NetworkMaager via nmcli.


Difference between the output of ifconfig and ipconfig:

Functionality: The ipconfig command displays all the currently connected network interfaces whether they are active or not. 

On the other hand, the ifconfig command displays only the enabled network interfaces that are connected to the system.



This article covers how to install Zimbra mail server on CentOS & RHEL systems. Zimbra offers two editions, the commercially supported edition called 'Network Edition' & a free/open-source version called 'Open Source Edition'. 

Zimbra Collaboration Suite (ZCS) is a collaborative software suite that includes a mail & chat server with a web client.


Main components of Zimbra Mail and Collaboration Server are:

1. Zimbra Core: These are basic libraries, utilities, monitoring tools, and basic configuration files.

2. Zimbra LDAP: This has the OpenLDAP LDAP directory server that provides authentication and configs store for users and other zimbra components.

3. Zimbra MTA (mail routing server): Has Postfix mail transfer agent (MTA) that receives email via SMTP and routes each message to the appropriate Zimbra mailbox server using Local Mail Transfer Protocol (LMTP). It also includes the anti-virus and anti-spam components.

4. Zimbra Store (Zimbra server): The mailbox server includes Data store, Message store and Index store for the mailboxes on the server. When a mail arrives, the Zimbra server schedules a thread to have the message indexed in the index store.

5. Zimbra-SNMP: This is an optional component for for monitoring and it runs on every server (Zimbra server, Zimbra LDAP, Zimbra MTA). Swatch is used to watch the syslog output to generate SNMP traps.

6. Zimbra Logger: This is an optional component for the mailbox server. It installs tools for syslog aggregation, reporting, and message tracing. This is required for the message trace feature.


To Edit your hosts file on Ubuntu:

1. $ nano –w /etc/hosts

You should have this line

Ip_address server.domain.com server

Update it as per your server information.

2. Press ctrl key + o to save

3. Press ctrl key + x to exit

4. Restart your server to take effect all the changes

$ reboot


To install Zimbra on Ubuntu server:

1. Install Zimbra prerequisites

$ apt-get update 

$ apt-get install libgmp10 libperl5.18 libaio1 pax sysstat sqlite3

2. Download Zimbra Email Server

$ wget https://files.zimbra.com/downloads/8.6.0_GA/zcs8.6.0_GA_1153.UBUNTU14_64.20141215151116.tgz

3. Unpack the file

tar xzvf zcs-8.6.0_GA_1153.UBUNTU14_64.20141215151116.tgz

4. Go to Zimbra forder

cd zcs-8.6.0_GA_1153.UBUNTU14_64.20141215151116

5. Begin installation

./install.sh

NOTE : While running the install.sh command you will be prompted with the following questions.

Do you agree with the terms of the software license agreements? [N] Y

Install zimbra-ldap [Y] Enter

Install zimbra-logger [Y] Enter

Install zimbra-mta [Y] Enter

Install zimbra-dnscache [Y] N Enter

Install zimbra-snmp [Y] Enter

Install zimbra-store [Y] Enter

Install zimbra-apache [Y] Enter

Install zimbra-spell [Y] Enter

Install zimbra-memcached [Y] Enter

Install zimbra-proxy [Y] Enter

The System will be modified. Continue? [N] Y Enter

NOTE: Do not install dnscache because we already installed bind9.

Sometimes it takes for a while to install some packages.

You will receive this error:

DNS ERROR resolving server.domain.com server

Change hostname [Yes] Enter

Please enter the logical hostname for this host [server.domain.com] domain.com

Ports conflicts detected! – Press Enter /Return key to continue Enter

Setup a password for admin account.



This article covers how you can easily adjust the time, date, and time zone of your system in CentOS 8.

To change the time zone in Linux systems use the sudo timedatectl set-timezone command followed by the long name of the time zone you want to set.


How to Synchronize Time on Installed Linux Operating Systems ?

1. On the Linux machine, log in as root.

2. Run the ntpdate -u <ntpserver> command to update the machine clock. For example, ntpdate -u ntp-time.

3. Open the /etc/ntp. conf file and add the NTP servers used in your environment.

4. Run the service ntpd start command to start the NTP service and implement you configuration changes.


Importance of man command in Linux:

man command in Linux is used to display the user manual of any command that we can run on the terminal. 

It provides a detailed view of the command which includes NAME, SYNOPSIS, DESCRIPTION, OPTIONS, EXIT STATUS, RETURN VALUES, ERRORS, FILES, VERSIONS, EXAMPLES, AUTHORS.



This article covers how to install the Opera browser using different ways on CentOS 8. We have also shown how you can install packages by using the wget command. Opera browser is amazing on your CentOS 8 system.


To install Opera browser on CentOS:

1. Add Opera YUM repository

Run the following commands to manually add the Opera RPM repository to your RHEL / CentOS 8 system.

$ sudo tee /etc/yum.repos.d/opera.repo <<RPMREPO

[opera]

name=Opera packages

type=rpm-md

baseurl=https://rpm.opera.com/rpm

gpgcheck=1

gpgkey=https://rpm.opera.com/rpmrepo.key

enabled=1

RPMREPO

2. Install Opera Browser on RHEL 8 / CentOS 8

Use yum package manager command to install Opera Browser on RHEL 8 / CentOS 8.

$ sudo yum -y install opera-stable

3. Wait for the installation to complete then launch the browser from the CLI:

$ opera 



This article covers how to setup the NFS server and client on Mint. You will learn how to install the NFS server and client, configure and share NFS export directories, and mount/unmount the NFS shares on the client.

Network File System (NFS), is a distributed file system that allows various remote systems to access a file share. We all know that files should be stored on a central server for security and ease of backup. NFS provides us with a file sharing service that is easily managed and controls client access to resources.


To Install the NFS Client on the Client Systems:

1. Install the NFS-Common Package. As is the norm, begin by updating the system packages and repositories before anything else.

2. Create a NFS Mount Point on Client.

3. Mount NFS Share on Client System.

4. Testing the NFS Share on Client System.


A Network File System (NFS) allows remote hosts to mount file systems over a network and interact with those file systems as though they are mounted locally. This enables system administrators to consolidate resources onto centralized servers on the network.


Benefits of setting up an NFS server:

1. Enables multiple computers to use the same files, so everyone on the network can access the same data.

2. Reduces storage costs by having computers share applications instead of needing local disk space for each user application.



This article covers how to install Wine on CentOS 8. With the use of this package, you can easily use the native Windows applications on CentOS 8. However, you can also remove this package from your CentOS 8 system to conserve the memory whenever you want.


How to Install Wine 4 on CentOS 8:

Install EPEL Repos on CentOS 8

Wine is not included in the default CentOS 8 repositories but however available on EPEL repos. Therefore, run the command below to install EPEL repos:

$ dnf install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm


To run Wine on CentOS 8:

Wine command takes the following syntax.

$ wine program [arguments]

To obtain help on Wine usage;

$ wine --help

Consult man pages for Wine for more insight.

$ man wine

Before you can use Wine to run Windows applications, reboot your system to setup the Wine environment.

$ systemctl reboot



This article covers how to install python2 and python3 on CentOS 8. By default, python2 and python3 are not installed on CentOS 8. To install both, you need to install all python packages separately according to python versions. Also, you can run python2 and python3 environments on your system. 

The 'alternatives --auto python' command is used to set any python version as the default. 


To run Python in Linux:

A widely used way to run Python code is through an interactive session. 

To start a Python interactive session, just open a command-line or terminal and then type in python, or python3 depending on your Python installation, and then hit Enter .


Python comes preinstalled on most Linux distributions, and is available as a package on all others. 

However there are certain features you might want to use that are not available on your distro's package. 

You can easily compile the latest version of Python from source.


Installing Python 3 on Linux:

1. To see which version of Python 3 you have installed, open a command prompt and run

$ python3 --version

2. If you are using Ubuntu 16.10 or newer, then you can easily install Python 3.6 with the following commands:

$ sudo apt-get update

$ sudo apt-get install python3.6

3. If you're using another version of Ubuntu (e.g. the latest LTS release) or you want to use a more current Python, we recommend using the deadsnakes PPA to install Python 3.8:

$ sudo apt-get install software-properties-common

$ sudo add-apt-repository ppa:deadsnakes/ppa

$ sudo apt-get update

$ sudo apt-get install python3.8

4. If you are using other Linux distribution, chances are you already have Python 3 pre-installed as well. If not, use your distribution's package manager. For example on Fedora, you would use dnf:

$ sudo dnf install python3


To see if pip is installed, open a command prompt and run:

$ command -v pip



This article covers how to #install Chrony on Linux Mint 20. Once it will be installed on your system, its daemon will silently work in the background to synchronize your system's clock with the #NTP server. 

However, if you do not want Chrony to perform this job any longer, then you can simply uninstall it as well.

Chrony is a flexible implementation of the Network Time Protocol (NTP). 

It is used to synchronize the system clock from different NTP servers, reference clocks or via manual input.


Chrony comes with two programs:

1. chronyc – command line interface for chrony

2. chronyd – daemon that can be started at boot time


How to Install #Chrony in #Linux :

On some systems, chrony may be installed by default. Still if the package is missing, you can easily install it. 


You can install chrony Using your default package manager tool on your respective Linux distributions using following command:

# yum -y install chrony    [On CentOS/RHEL]

# apt install chrony       [On Debian/Ubuntu]

# dnf -y install chrony    [On Fedora 22+]


To check the status of chronyd use the following command:

# systemctl status chronyd      [On SystemD]

# /etc/init.d/chronyd status    [On Init]


If you want to enable chrony daemon upon boot, you can use the following command:

# systemctl enable chronyd       [On SystemD]

# chkconfig --add chronyd        [On Init]


How to Check Chrony Synchronization in Linux ?

To check if chrony is actually synchronized, we will use it's command line program chronyc, which has the tracking option which will provide relevant information:

# chronyc tracking


To check information about chrony’s sources, you can issue the following command:

# chronyc sources



This article covers how to assign and remove multiple IP addresses to and from a single NIC. Based on your preferences, you can either assign the multiple IP addresses temporarily or permanently.

There's no simple command that you can run to determine whether the IP address on a Linux system is assigned by DHCP or static. 

If it changes when the system restarts, it's clearly dynamically assigned, but even a dynamic address has some resistance to change. 

The best way is to look at the configuration file.


To add a static route in Linux:

1. Use the route command with the –p option to add a persistent route: # route -p add default ip-address.

2. Use the route command with the –name option to add a persistent route by specifying a name rather than destination and gateway: # route -p add destination-address gateway-address -name name.


What is ip route command in Linux?

ip route is used to manipulate entries in the kernel routing tables. 

Route types: 

1. unicast - the route entry describes real paths to the destinations covered by the route prefix. 

2. unreachable - these destinations are unreachable. 

Packets are discarded and the ICMP message host unreachable is generated.



This article will cover how to install and remove the PostgreSQL server and create a database in PostgreSQL on CentOS 8. Also you will learn how to add tables in the database by using the SQL query.

PostgreSQL is available from CentOS 8's default AppStream software repository, and there are multiple versions which you can install. 

You can choose between these versions by enabling the appropriate collection of packages and dependencies that align with the version you want to install, with each collection referred to as a module stream.


To List out the available streams for the postgresql module using the dnf command:

$ dnf module list postgresql



This article covers the different methods for the installation of Google Chrome on the CentOS 8 system using the terminal commands and graphical method. 

Once the installation of chrome is complete, now you can feel free to add chrome extensions and favorite themes from the web store of Google Chrome.


To install Google Chrome 78 on a RHEL/CentOS/Fedora Linux:

1. Open the Terminal application. Grab 64bit Google Chrome installer.

2. Type the following command to download 64 bit version of Google Chrome:

wget https://dl.google.com/linux/direct/google-chrome-stable_current_x86_64.rpm

3. Install Google Chrome and its dependencies on a CentOS/RHEL, type:

sudo yum install ./google-chrome-stable_current_*.rpm

4. Start Google Chrome from the CLI:

google-chrome &


To upgrade Google Chrome from an older version:

You can simply update it by typing the following yum command:

$ sudo yum update google-chrome-stable

OR use the following dnf command to update it on a Fedora Linux:

$ sudo dnf update google-chrome-stable


To uninstall Chrome from Ubuntu:

1. Open the Terminal: It should be present on your desktop or taskbar.

2. Type sudo apt-get purge google-chrome-stable and press Enter to uninstall the Chrome browser.

3. Type sudo apt-get autoremove and press Enter to clean up the Package Manager to ensure that there are no lingering files.



This article will guide you on how to configure the NTP server on the #Ubuntu machine and then sync a clock of NTP client machine. Now you can easily set up NTP server and connect multiple client machines with it for time synchronization.

The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.

NTP is intended to synchronize all participating computers to within a few milliseconds of Coordinated Universal Time (UTC).


How do I start #NTP on Linux?

In order to add command line options to the ntpd service (/etc/init. d/ntpd), one has to edit /etc/sysconfig/ntpd file and add the desired option to the OPTIONS variable, and restart the service via 'service ntpd restart'.


What port does NTP use?

NTP time servers work within the TCP/IP suite and rely on User Datagram Protocol (UDP) port 123. NTP servers are normally dedicated NTP devices that use a single time reference to which they can synchronize a network. 

This time reference is most often a Coordinated Universal Time (UTC) source.


To Sync NTP client with server via command line:

1. Edit the /etc/ntp.

2. Search for the lines beginning server .

3. Replace the server entries with the IP address or hostname of the NTP server or servers with which you want to synchronize.

4. Save the file.

5. Configure the NTP client service to start at run level 3 when the appliance boots.



This article will guide you on the different methods to find the private IP address in CentOS 8.


Different ways to display IP addresses in Centos:

1. Using ifconfig command. The ifconfig command is the most commonly used command for displaying and modifying IP addresses on the system.

2. Using ip command.

3. Using the hostname command.

4. using nmcli command.

5. Using ip route show command.


To configure a static IP address on CentOS 7 / RHEL 7:

1. Create a file named /etc/sysconfig/network-scripts/ifcfg-eth0 as follows:

2. DEVICE=eth0.

3. BOOTPROTO=none.

4. ONBOOT=yes.

5. PREFIX=24.

6. IPADDR=192.168.x.xxx.

7. Restart network service: systemctl restart network.


Commands will get you the private IP address of your interfaces:

i. ifconfig -a.

ii. ip addr (ip a)

iii. hostname -I | awk '{print $1}'

iv. (Fedora) Wifi-Settings→ click the setting icon next to the Wifi name that you are connected to → Ipv4 and Ipv6 both can be seen.

v. nmcli -p device show.



This article will guide you on how to assign multiple IP addresses to a single NIC in Ubuntu OS. Now you can allocate multiple IP addresses to a single NIC.

To change your IP address on #Linux, use the "ifconfig" command followed by the name of your network interface and the new IP #address to be changed on your computer. 

To assign the subnet mask, you can either add a "netmask" clause followed by the subnet mask or use the CIDR notation directly.

The ifconfig command can be used from the #command line either to assign an address to a #network interface or to configure or display the current network interface configuration information. 

The ifconfig command must be used at system startup to define the network address of each interface present on a machine.


To determine my IP address in Linux :

1. ifconfig -a.

2. ip addr (ip a).

3. hostname -I | awk '{print $1}'.

4. ip route get 1.2.

5. nmcli -p device show.


To add secondary IP address permanently on Ubuntu system, just edit /etc/network/interfaces file and add the requires IP details. 

Verify the newly added IP address. # ifconfig eth0



This guide will help you on how to #install the LAMP stack (Linux, Apache, MariaDB, and PHP ) in your #Debian system. 

LAMP stands for Linux, Apache, MySQL, and PHP. Together, they provide a proven set of software for delivering high-performance web applications.

For a web application to work smoothly, it has to include an operating system, a web server, a database, and a programming language. 

A LAMP Stack is a set of open-source software that can be used to create websites and web applications. 

LAMP is an acronym, and these stacks typically consist of the Linux operating system, the Apache HTTP Server, the MySQL relational database management system, and the PHP programming language.

To Install #LAMP stack on Ubuntu:

1. Update your system. sudo apt-get update.

2. Install Mysql. sudo apt-get install mysql-server mysql-client libmysqlclient-dev.

3. Install #Apache server.

4. Install #PHP (php7.0 latest version of PHP).

5. Install #Phpmyadmin (for #database).



This article will guide you on how you can setup NFS server and client in Debian 10 system. Also, you will learn steps to install the NFS server and client, configure NFS shared directories, and mount/unmount the NFS shares on the client system.

Configuring a system to share files and directories using NFS is straightforward. 

NFS uses port 2049. NFSv3 and NFSv2 use the portmapper service on TCP or UDP port 111.

Every filesystem being exported to remote users via NFS, as well as the access rights relating to those filesystems, is located in the /etc/exports file.

To check #NFS mount #Linux:

1. Use showmount to show NFS shares.

2. Use exportfs to show NFS shares.

3. Use master export file /var/lib/nfs/etab to show NFS shares.

4. Use mount to list NFS mount points.

5. Use nfsstat to list NFS mount points.

6. Use /proc/mounts to list NFS mount points.




This article will guide you on methods to uninstall a #package using #Yum. You need to just type the package name with root privileges. Moreover, we have also seen how to remove a single package, multiple, and group by using the Yum package manager.

apt remove just removes the binaries of a package. 

It leaves residue configuration files. apt purge removes everything related to a package including the configuration files.

To uninstall a program in #Linux Mint terminal:

1. Uninstall software in Linux mint from the main menu.

2. Confirm that you want to #remove the package.

3. Open the Software Manager.

4. Search for a program to remove using the software manager.

5. Remove software in Linux #Mint using the software manager.

6. Open Synaptic package manager.



This article will guide you on how to install and configure the Zabbix server on #Linux. You have also learned how to install and configure the Zabbix agent on the Zabbix server and the client #machines. Now you can easily keep track of the servers and monitor their health.

Zabbix server is the central process of #Zabbix software. The server performs the polling and trapping of data, it calculates triggers, sends notifications to users.

The server can itself remotely check networked services (such as web servers and mail servers) using simple service checks.

You can now start the Zabbix server and agent by running the commands:

sudo systemctl start zabbix-server.

sudo systemctl start zabbix-agent.



This article will guide you on how to check the #memory #usage on the #CentOS 8 system. Moreover, we have executed different commands such as cat, free, #vmstat, top and htop that are used to display the memory information. 

sudo apt-get clean clears out the local #repository of retrieved package files.It removes everything but the lock file from /var/cache/apt/archives/ and /var/cache/apt/archives/partial/. Another possibility to see what happens when we use the command sudo apt-get clean is to simulate the execution with the -s -option.

Using these commands, you can easily get information about your system RAM, and CPU.

Commands to check memory usage on Linux:

1. free command. The free command is the most simple and easy to use command to check memory usage on linux.

2. /proc/meminfo. The next way to check memory usage is to read the /proc/meminfo file. 3. vmstat. The vmstat command with the s option, lays out the memory usage statistics much like the proc command.

5. top command.

5. htop.



This article will guide you on how to install and configure the Odoo14 on #Ubuntu 20.04 system. Also you will learn how to install required #PostgreSQL and wkhtmltopdf packages on your system. 

1. Odoo Community Edition is the free basic version of Odoo supported by open source software. 

2. #Odoo #CRM (Customer Relationship Management) system is a powerful browser-based sales software designed to increase organisational efficiency. Odoo, contains all of the applications that your sales, marketing, accounts department and management teams need in the one place.

3. Once all dependencies are set up, Odoo can be launched by running odoo-bin , the command-line interface of the server. It is located at the root of the Odoo Community directory.

4. Once Odoo installed, you can verify the service is up and running and is enabled to automatically start at system #boot. 

5. By default, Odoo listens on port 8069 and you can verify it using the netstat or ss tools. 

This is another way to confirm that Odoo is up and running.



This article will guide you on how to #install and configure #HAproxy load balancer on the #Linux system. 

You will learn the basic setup and configuration of HAproxy as a load balancer for #Apache web servers. Also, we looked at some commands for managing the HAproxy server. In the end, we tested the load balancing through the browser and the #curl command. 

HAProxy is free, open source #software that provides a high availability #load #balancer and proxy server for #TCP and HTTP-based applications that spreads requests across multiple servers.

To Deploy on Linux :

1. Download the source code of HAProxy.

2. Unzip the file into the desired location tar xvzf haproxy-1.8-dev1.

3. Compile the source code.

4. Create config file haproxy.cfg with the configuration details.

5. Start the haproxy with ./haproxy -f haproxy.

6. Access the status page on http:localhost:9999/stats.



This article will guide you on how to #install #MySQL server on Debian 10 #Linux system. Also we looked into how to secure the installation and connect with the MySQL shell. Using the Validate password #plugin you can make a more secure database MySQL password #authentication.

MySQL is an #RDBMS tostore, retrieve, modify and administrate a database usingSQL.

The mysql #command:

1. -h followed by the server host name (server.linuxapt.com).

2. -u followed by the account user name (use your MySQL username).

3. -p which tells mysql to prompt for a password.

4. database the name of the database (use your database name).



This article will guide you on how to #install Zimbra on Ubuntu. Zimbra is an open-source #mail server that offers several features. It is recommended to install it in a #machine that has enough memory, processor, and disk space available. 

To install and configure #Zimbra mail server:

1. Install System Packages.

2. Configure System #Hostname.

3. Add a Static IP Address.

4. Disable Unwanted Services.

5. Install Zimbra Collaboration Suite Open Source Edition.

6. Zimba Initial Configuration.



This article will guide you on how to configure Squid #proxy server on a Linux system. There is a lot more you can do with Squid proxy server. 

Although primarily used for HTTP and FTP, #Squid includes limited support for several other protocols including Internet Gopher, SSL, TLS and HTTPS. Squid does not support the #SOCKS protocol, unlike Privoxy, with which Squid can be used in order to provide SOCKS support.

The squid. conf file defines the configuration for squid. The configuration includes (but not limited to) HTTP port number, the ICP request port number, incoming and outgoing requests, information about #firewall access, and various timeout information.

To connect Squid proxy:

i. Tools>Options>Advanced>Network>Settings.

ii. Select Manual proxy configuration and tick the 'use this proxy server for all protocols' box.

iii. Under HTTP Proxy: add the squid listening IP address, 10.0. 0.1. In the Port: section add the squid listening port 3128.

iv. Click OK to save the changes.



This article will guide you on steps to #install the Squid proxy server on your #Linux machine. You will also learn how to uninstall the Squid #proxy server in the #Ubuntu #machine and manage Squid services.

Squid is a caching proxy for the Web supporting HTTP, #HTTPS, FTP, and more. It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages.

It is most often used in conjunction with a traditional LAMP stack (Linux, Apache, MySQL, PHP), and can be used to filter traffic on #HTTP, FTP, and HTTPS, and increase the speed (thus lower the response time) for a web server via caching.

To clear #squid proxy cache:

1. Stop the #httpd and squid services.

2. Delete the contents of the cache as follows: # rm -Rf /var/cache/rhn/*

3. Restart the squid and httpd services.



This article will guide you on how to start, stop, and restart the #network service on different Linux distribution like Ubuntu, #Debian, Linux Mint, and CentOS 8. Moreover, you can troubleshoot the network #error through the #NetworkManager tool on #CentOS 8.

Please don't stop services if you have a remote ssh connection that may create a problem.

Restarting networking on a desktop machine will cause dbus and a bunch of #service to stop and never be started again, usually leading to the whole system being unusable.

To restart a Linux service:

1. Linux provides fine-grained control over system services through #systemd, using the systemctl command.

2. To verify whether a service is active or not, run this command: sudo systemctl status apache2.

3. To stop and restart the service in Linux, use the command: sudo systemctl restart SERVICE_NAME.



This article will guide you on steps to #install and configure #Apache on #Linux server.

Apache is one of the most popular web servers that allows you to run a secure website without too much of a headache.

#HTTPD is a program that is (essentially) a program known as Apache Web server. The only difference I can think of is that on Ubuntu/Debian the binary is called apache2 instead of httpd which is generally what it is referred to as on RedHat/CentOS. Functionally they are both 100% the same thing.

Apache server root will be located in /etc/httpd. The path to the apache #program will be /usr/sbin/httpd. In the document root three directories are created: cgi-bin, html and icons.

By default, Apache web server is instructed to listen for incoming connection and bind on port 80. If you opt for the TLS configuration, the server will listen for secure connections on port 443.

To start Apache server on Debian / Ubuntu Linux Specific Commands to Start/Stop/Restart Apache:

1. Restart Apache 2 web server, enter: # /etc/init.d/apache2 restart. $ sudo /etc/init.d/apache2 restart.

2. To stop Apache 2 web server, enter: # /etc/init.d/apache2 stop.

3. To start Apache 2 web server, enter: # /etc/init.d/apache2 start.



This article will guide you on steps to install #MariaDB on the #Linux operating system. 

MariaDB offers more and better storage engines. NoSQL support, provided by Cassandra, allows you to run SQL and NoSQL in a single database system. MariaDB also supports TokuDB, which can handle big data for large organizations and corporate users.

As a columnar database, MariaDB ColumnStore stores table data in columns rather than rows. Data partitioning by columns is also called Vertical Partitioning.

MariaDB is a drop in place replacement for #MySQL, but you can also install it alongside MySQL. 

To install MariaDB on #Ubuntu 18.04, follow these steps:

1. Update packages index. sudo apt update.

2. Once the packages list is updated, install MariaDB by issuing the following command: sudo apt install mariadb-server.

3. The MariaDB service will start automatically.



This article will guide you on steps to perform Perl installation on #CentOS 8. You will also learn how to create and execute the #Perl #script on your CentOS system by using the terminal #commands.

Perl is a programming language that can be used to perform tasks that would be difficult or cumbersome on the command line.

To run a Perl script in Linux:

1. Run the "perl" command with the Perl script included in the command line.

2. Run the "perl" command with the Perl script supplied from the standard input stream.

3. Run the "perl" command with the Perl script supplied in a file.

4. Run Perl script files as commands.



This article will guide you on the steps to disable SELinux running on your CentOS 7, RHEL 7 and Fedora Linux. Security-Enhanced #Linux (#SELinux) is a security architecture for Linux #systems that allows administrators to have more control over who can access the system. It was originally developed by the United States National Security Agency (#NSA) as a series of patches to the Linux #kernel using Linux #Security Modules (LSM).



This article will guide you on the steps to install openssh server (sshd) and clients on CentOS Linux using the yum command. The #ssh #command provides a secure encrypted connection between two hosts over an insecure #network. This connection can also be used for #terminal access, file transfers, and for tunneling other applications. Graphical X11 applications can also be run securely over SSH from a remote location.



This article will guide you on how to run commands as root user using nonuser, su, and sudo utilities.



MariaDB is a very popular Database management system which is open source. It is well know as being stable and in this context , we will analyze how to get it running on your CentOS 7 Linux machine.




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