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Install MySQL Version 8 on Red Hat Enterprise Linux 8 - Step by Step Process ?

This article covers how to Install MySQL Version 8 on Red Hat Enterprise Linux 8. Now, you should now have a fully functioning MySQL server version 8 running on your Server.


To Install MySQL 8.0 On CentOS 8 / RHEL 8:

1. Install MySQL 8.0 from MySQL Dev Community

Add the official repository of MySQL to install the MySQL community server:

$ rpm -ivh https://dev.mysql.com/get/mysql80-community-release-el8-1.noarch.rpm

Make sure the MySQL repository has been added and enabled by using the following command:

$ yum repolist all | grep mysql | grep enabled


To Manage MySQL server Service on Linux:

1. After the installation of MySQL, start MySQL server service using the following command:

$ systemctl start mysqld

2. The below command will Enable MySQL server at system startup:

$ systemctl enable mysqld

3. Verify that MySQL server is started using the following command:

$ systemctl status mysqld


Manage Firewall Rules with UFW on Red Hat Enterprise Linux 8

This article covers how to secure Red Hat Enterprise Linux 8 with UFW. UFW may not be intended to provide complete firewall functionality, but it does provide an easy way to create and manage simple firewall rules.

A firewall is a way to protect machines from any unwanted traffic from outside. 

It enables users to control incoming network traffic on host machines by defining a set of firewall rules. 

These rules are used to sort the incoming traffic and either block it or allow through.

Note that firewalld with nftables backend does not support passing custom nftables rules to firewalld, using the --direct option.


How to start, stop, restart firewalld service on an RHEL 8?

By now you know about firewalld zones, services, and how to view the defaults. It is time to activate and configure our firewall.

1. Start and enable firewalld

$ sudo systemctl start firewalld
$ sudo systemctl enable firewalld

2. Stop and disable firewalld

$ sudo systemctl stop firewalld
$ sudo systemctl disable firewalld

3. Check the firewalld status

$ sudo firewall-cmd --state

4. Command to reload a firewalld configuration when you make change to rules

$ sudo firewall-cmd --reload

5. Get the status of the firewalld service

$ sudo systemctl status firewalld


When to use firewalld, nftables, or iptables:

1. firewalld: Use the firewalld utility for simple firewall use cases. The utility is easy to use and covers the typical use cases for these scenarios.

2. nftables: Use the nftables utility to set up complex and performance critical firewalls, such as for a whole network.

3. iptables: The iptables utility on Red Hat Enterprise Linux 8 uses the nf_tables kernel API instead of the legacy back end. 

The nf_tables API provides backward compatibility so that scripts that use iptables commands still work on Red Hat Enterprise Linux 8. For new firewall scripts, Red Hat recommends to use nftables.


Install LibreOffice on CentOS 8 - Step by Step Process ?

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]


Install VirtualBox on CentOS 8 - Step by Step Process ?

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


Flush DNS Cache on Ubuntu 20.04 - Step by Step process ?

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


Download YouTube Videos on Ubuntu Linux - How to do it ?

This article covers how you can download YouTube videos on Linux using the youtube-dl utility. The youtube-dl is a handy utility with a large feature set. However, there is a lot more you can do with this utility. To explore more features, visit its official documentation . To play the downloaded videos, you can use any media players like VLC , FFmpeg , and so on.

youtube-dl is a command-line program that lets you easily download videos and audio from more than a thousand websites. 


youtube-dl is a Python based small command-line tool that allows to download videos from YouTube.com, Dailymotion, Google Video, Photobucket, Facebook, Yahoo, Metacafe, Depositfiles and few more similar sites. 

It written in pygtk and requires Python interpreter to run this program, it's not platform restricted. It should run on any Unix, Windows or in Mac OS X based systems.


To Install YouTube-DL in RHEL/CentOS and Fedora:

The youtube-dl program can be installed by enabling epel repository under your systems. Once enabled, you can install using 'yum' package manager tool:

$ yum install youtube-dl

Also, if you wish to add any third party repository, you can still install it right away using curl or wget command:

$ curl https://yt-dl.org/latest/youtube-dl -o /usr/local/bin/youtube-dl

OR

$ wget https://yt-dl.org/downloads/latest/youtube-dl -O /usr/local/bin/youtube-dl

Your system must have curl or wget packages installed to fetch the recent version youtube-dl file. If you don't have them, you may yum to get it.

After fetching the file, you need to set a executable permission on the script to execute properly:

$ chmod a+rx /usr/local/bin/youtube-dl


To Install YouTube-DL in Ubuntu/Linux Mint and Debian:

$ sudo add-apt-repository ppa:nilarimogard/webupd8
$ sudo apt-get update
$ sudo apt-get install youtube-dl

Also, instead using any third party PPA, you can use curl or wget command to install latest version of youtube-dl script:

$ sudo curl https://yt-dl.org/latest/youtube-dl -o /usr/local/bin/youtube-dl

OR

$ sudo wget https://yt-dl.org/downloads/latest/youtube-dl -O /usr/local/bin/youtube-dl

After downloading the script, set the executable permission:

$ sudo chmod a+rx /usr/local/bin/youtube-dl


To Update YouTube-DL,

Youtube-dl itself can be updated to the latest version using the following command:

$ youtube-dl -U


Install Cockpit on Ubuntu 20.04 - Step by step process to do this ?

This article covers how to install Cockpit on Ubuntu 20.04 system. Cockpit is a free and open source web console tool for Linux administrators and used for day to day administrative and operations tasks. 


To Install the Cockpit package on Ubuntu 20.04 LTS Server, run the command:

$ sudo apt update
$ sudo apt install cockpit -y

Once cockpit package is installed successfully then start its service using the following systemctl command,

$ sudo systemctl start cockpit

Run the following to verify the status of cockpit service,

$ sudo systemctl status cockpit


Features of Cockpit:

Cockpit allows you to perform:

1. Service Management – Start, stop, restart, reload, disable, enable, mask e.t.c

2. User Account Management – Add users, delete, Lock, assign Administrator role, set password, force password change, Add Public SSH keys e.t.c.

3. Firewall Management

4. Cockpit Container management

5. SELinux Policy management

6. Journal v2

7. iSCSI Initiator configurations

8. SOS-reporting

9. NFS Client setup

10. Configure OpenConnect VPN Server

11. Privileged Actions – Shutdown, Restart system

12. Join Machine to Domain

13. Hardware Device Management

14. System Updates for dnf, yum, apt hosts

15. Manage the Kubernetes Node


Install XAMPP on CentOS 8 - Step by Step process to do this ?

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


Install Memcached on Ubuntu 20.04 - Step by step process ?

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


Install and Use Firewalld in CentOS / RHEL - Step by step process to implement it ?

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.


Install Sublime Text Editor on CentOS 8 - Step by Step process to do it ?

This article covers how to install sublime text editor on the CentOS 8 system through the terminal. Sublime text editor is quite similar to vim editor. Sublime text has a built-in Python API available in Windows, Linux, and Mac OS.


To install Sublime Text on Ubuntu:

1. Install the GPG key:

$ wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add -

2. Ensure apt is set up to work with https sources:

$ sudo apt-get install apt-transport-https

3. Select the channel to use:

i. Stable

$ echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

ii. Dev

$ echo "deb https://download.sublimetext.com/ apt/dev/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

4. Update apt sources and install Sublime Text:

$ sudo apt-get update
$ sudo apt-get install sublime-text


To fix yum-config-manager command not found:

You need to Install yum-utils by running the command below:

$ yum install yum-utils


Setup Teampass Passwords Manager on Ubuntu 20.04 - Do it Now ?

This article covers perform the installation of TeamPass using the LAMP stack on Ubuntu. Now you can easily manage your credentials within your Organization to save credentials and manage access to every individual. 

TeamPass is a Collaborative Passwords Manager used for managing passwords and sharing them among team members.


To Download Teampass on Ubuntu:

1. Start by cloning the Teampass repository to your web server root directory as shown below;

$ git clone https://github.com/nilsteampassnet/TeamPass.git /var/www/html/teampass

2. Set the ownership of the teampass web directory to web server user (www-data)

$ chown -R www-data.www-data /var/www/html/teampass/

3. Next, edit the /etc/php/7.2/apache2/php.ini configuration file and increase the script execution time from 30 to 60 secs.

vim /etc/php/7.2/apache2/php.ini
...
;max_execution_time = 30
max_execution_time = 60
...

4. Restart Apache web server

$ systemctl restart apache2


To Finalize TeamPass installation on Ubuntu:

Final installation of Teampass can be done from the browser. 

Hence, navigate to the browser and enter the Teampass server URL, 

http://Server_IP/teampass

This will redirect you to Teampass welcome page


Install TeamViewer on CentOS 8 - Step by Step process to get it done ?

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


Install Skype on CentOS 8 - Step by Step process to implement it ?

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.


Install Nginx on Ubuntu 20.04 - Step by Step process to implement it ?

This article covers how to install Nginx on the Ubuntu system. Also, you will learn how to configure the firewall and manage Nginx services. 

Finally, you will see how to uninstall Nginx in case you no longer need it in your system.

Nginx is a free, open-source Linux application for web servers. It works as a reverse proxy server by directing web traffic to specific servers.

Also, Nginx is used for security and load-balancing, but can also function independently as a web server.


To Install Nginx From Ubuntu Repositories:

1. Update Software Repositories

It is important to refresh the repository lists before installing new software. This helps make sure that the latest updates and patches are installed.

Open a terminal window and enter the following:

$ sudo apt-get update

2. Nginx is included in the Ubuntu 20.04 default repositories. Install it by entering the following command:

$ sudo apt-get install nginx


How to manage Nginx on Ubuntu ?

The behavior of Nginx can be adjusted. Use this to start or stop Nginx, or to enable or disable Nginx at boot.

Start by checking the status of the Nginx service:

$ sudo systemctl status nginx

If the status displays active (running), Nginx has already been started. 

Press CTRL+z to exit the status display.

If Nginx is not running, use the following command to launch the Nginx service:

$ sudo systemctl start nginx

To set Nginx to load when the system starts, enter the following:

$ sudo systemctl enable nginx

To stop the Nginx service, enter the following:

$ sudo systemctl stop nginx

To prevent Nginx from loading when the system boots:

$ sudo systemctl disable nginx

To reload the Nginx service (used to apply configuration changes):

$ sudo systemctl reload nginx

For a hard restart of Nginx:

$ sudo systemctl restart nginx

To Test the Configuration

$ sudo nginx –t

The system should report that the configuration file syntax is OK, and that the configuration file test is successful.


Install Apache Web Server on CentOS 8 - Step by Step process to do it ?

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.


Assign Multiple IP Addresses to Single NIC in Linux Mint 20 - How to Do it ?

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.


Install Zimbra Collaboration Suite (ZCS) on CentOS 8 - Step by step process to do it ?

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.


Create and Run a Shell Script in CentOS 8 - Step by step process to do it ?

This article covers how to create and run a simple shell script in CentOS 8 system. With this, you can easily create and run even complex scripts and automate repetitive tasks. 

If you are using other Linux distributions, you can visit our posts on how to create and run a shell script in Ubuntu , Debian , and Linux Mint .


An SH file is a script programmed for bash, a type of Unix shell (Bourne-Again SHell). It contains instructions written in the Bash language and can be executed by typing text commands within the shell's command-line interface.


To write and execute a script:

1. Open the terminal. Go to the directory where you want to create your script.

2. Create a file with . sh extension.

3. Write the script in the file using an editor.

4. Make the script executable with command chmod +x <fileName>.

5. Run the script using ./<fileName>.


Change Date, Time, and Time Zone in CentOS 8 - How to do it ?

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.


Install Slack on CentOS 8 - Step by Step process to perform it ?

This article covers how you can easily install slack platform on your CentOS 8 Linux system through the command line. 

Using a slack application, team members of an organization can unify all conversations from different sources.


Slack is one of the most popular collaboration platforms in the world that brings all your communication together. 

Conversations in Slack are organized in channels. 

You can create channels for your teams, projects, topics, or any other purpose. 

You can search through everything that's been posted in channels or your messages. 

Slack also allows you to talk with your teammates over audio or video calls and share documents, images, videos, and other files.


To Install Slack on CentOS:

1. Update system

sudo yum -y update

2. Download and Install Slack on CentOS

sudo yum -y install wget

wget https://downloads.slack-edge.com/linux_releases/slack-3.4.0-0.1.fc21.x86_64.rpm

sudo  yum -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

sudo yum localinstall slack-3.4.0-0.1.fc21.x86_64.rpm

3. Start and Use Slack

Now that Slack is installed on your CentOS / RHEL 8 desktop, you can launch it through the command line,

$ slack


Install Opera Browser on CentOS 8 - Step by step process to perform it ?

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 


Configure NFS Server and Client on Linux Mint 20 - Step by Step process to do it ?

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.


Install Wine on CentOS 8 - Step by Step process to do it ?

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


5 Key Google Chrome Extensions

This article covers the key Google Chrome extensions which will definitely enhance your browsing experience and will make Google Chrome even more helpful and useful for you. Google Chrome extensions are programs that can be installed into Chrome in order to change the browser's functionality.

Adding to do lists or notes to Chrome. Password management. Making it easier to copy text from a site. Protect your privacy and making web browsing more secure.

Some extensions can be ethically dubious or even malicious, but Chrome features new restrictions on extension developers that should help mitigate that problem.


Unzip Files in Linux - How to perform it ?

This article covers how to use the unzip command on the CentOS 8 Linux system.

Also, you will learn various uses of the unzip command through which you can list ZIP archive content and extract files. You can utilize the unzip command according to your needs.


How to Create a ZIP File with the zip Command ?

To create a ZIP file, you need to tell zip the name of the archive file and which files to include in it. 

You don't need to add the ".zip" extension to the archive name, but it does no harm if you do.

To create a file called source_code.zip containing all the C source code files and header files in the current directory, you would use this command:

$ zip source_code *.c *.h


How to Unzip a ZIP File With the unzip Command ?

To extract the files from a ZIP file, use the unzip command, and provide the name of the ZIP file. 

Note that you do need to provide the ".zip" extension.

$ unzip source_code.zip


To Unzip on the Linux command line:

The simplest option that will extract the contents to current directory:

$ unzip backup.zip


To change the target directory for extracted material, use -d option followed by the desired directory:

$ unzip backup.zip -d ./restore-directory


To preview contents of zip file:

$ unzip -l backup.zip


If you don't want to unzip the whole file, then add the specific files to extract at the end:

$ unzip backup.zip file1 subdirectory/file2


The inverse of the above command. Unzip every file EXCEPT the ones specified after the -x modifier:

$ unzip backup.zip -x file1 subdirectory/file2


Unzipping a password protected file:

$ unzip -p mypassword backup.zip


Install and Run Python on CentOS 8 - How to do it ?

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


Install Chrony on Linux Mint - Easy steps to do it ?

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


Install and Use TermRecord on CentOS 8 - Do it now

This article Covers how to install the TermRecord application on CentOS 8. The TermRecord application allows you to better enjoy the recorded #Terminal content. 

TermRecord is a simple, open source, terminal session recorder with easy-to-share self-contained HTML output.

#TermRecord Stores these files as your own notes, email them to collaborators, use them as instructional examples, or whatever you wish.

TermRecord consumes output from the script command with timing information and can create a self-contained HTML file which replays the recorded session without needing to load anything from the web. 

These term sessions can be emailed and viewed on practically any device (including iPads etc.). 

The end user only needs a modern browser.


Features of TermRecord includes:

1. User friendly.

2. Detects the terminal size.

3. Nest sessions.

4. Cross-platform HTML-based output.

5. Stores the output as either JSON, embeddable JavaScript, or a static HTML file.

6. Written in Python.


To install on TermRecord #CentOS:

1. First of all, connect to your server via SSH and make sure that all of your system software is up to date. 

Run the following command to update the package list and upgrade all of your system software to the latest version available:

$ sudo yum update -y

2. Install Pip. 

Add the EPEL Repository:

$sudo yum install epel-release

Install pip:

$ sudo yum install python-pip

Once the installation has completed, you can verify that it was successful by using the following command:

$pip -V

3. Install TermRecord

Install TermRecord using the Python package manager (pip):

$sudo pip install TermRecord


How to use TermRecord on CentOS system ?

Taking a video of the terminal with TermRecord is rather simple, just run the following command (be attentive to capital letters):

TermRecord -o record.html

Note: We specify the output file in which the video will be recorded using the -o option. the .html format is the default format.

For more complex operations check out TermRecord --help


Assign Multiple IP Addresses to Single NIC in Debian 10 - How to do it ?

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.


Install PostgreSQL in CentOS 8 - Step by Step Process ?

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


Methods to Install Google Chrome on CentOS 8 ?

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.


Install MariaDB on CentOS 8 - Step by step process ?

This article will guide you on how to install MariaDB on your CentOS 8 system. Now you can create new databases and grant privileges to other database users. Also, you can add users and create new databases for web or desktop applications which will be written in PHP, Python, and so on.

In MariaDB replication is faster whereas in MySQL replication is slower. 

MariaDB is Open Source whereas MySQL uses some proprietary code in its Enterprise Edition. 

MariaDB doesn't support Data Masking and Dynamic column while MySQL supports it. Comparatively MariaDB is faster than MySQL.


To uninstall MariaDB and install mysql:

1. Purge mariadb sudo apt purge mariadb-* Remove all databases ('Yes' answer)

2. Purge mysql sudo apt purge mysql-*

3. Remove folders: sudo rm -r /usr/share/mysql/ sudo rm -r /etc/mysql/ sudo rm -r /lib/systemd/system/mysql.service.

4. Now you can try to install oracle mysql: sudo apt install mysql-server.


Process to configure an NTP server and client on Ubuntu 20.04 LTS ?

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.


Methods to Find Your Private IP Address in CentOS 8 ?

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.


Assign Multiple IP Addresses to Single NIC in Ubuntu 20.04 LTS - How to do it ?

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


Reboot CentOS 8 - Different methods to do it ?

This article will guide you on the different methods to reboot a #CentOS system which includes the keyboard shortcut, command line, and GUI based methods. 

There's nothing different in running sudo reboot in a instance versus on your own server. This action shouldn't cause any problems. 

You can shutdown/start/reboot the instance and your data will persist.

When used with no arguments, the shutdown command will power off the machine. sudo shutdown. 

The shutdown process starts after 1 minute, which is the default time interval.

It is recommended that you do a #reboot of your Server at least once per month. 

The Dedicated Hosting Servers are just computers, you would not leave your computer on for months straight without a single reboot, so the same rules apply for servers.


To reboot your Linux Server via #SSH:

1. Open Command Prompt. If you have a graphical interface, open the terminal by right-clicking the Desktop > left-clicking Open in terminal.

2. Use SSH Connection Issue reboot Command. In a terminal window, type: ssh –t user@server.com 'sudo reboot'.


Display System and Hardware Details in CentOS 8 - How to do it ?

This article will guide you on different methods to retrieve information about your #Linux system and the underlying #hardware devices. These procedures will help you check the specifications of your computer machine and you can easily know either the hardware device or computer software is compatible with your working system or not.

The Linux kernel is the main component of a Linux operating system (OS) and is the core interface between a computer's hardware and its processes.


To  find system information in #Centos:

1. To know only system name, you can use uname command without any switch will print system information or uname -s #command will print the kernel name of your system. 

2. To view your network hostname, use '-n' switch with uname command as shown. 

3. To get information about kernel-version, use '-v' switch.


Install Linux, Apache, MariaDB, PHP (LAMP) Stack on Debian 10 - Step by step process to do it ?

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).


Methods to log out of CentOS 8 ?

This article will guide you on different methods to log out of the #CentOS 8 #Linux system. Therefore, If you want to close the current user session then, Logging out of the system is the best choice. 

The main difference between these tools is that kill terminates processes based on Process ID number (PID), while the killall and pkill commands terminate running processes based on their names and other attributes.

To exit CentOS 7:

i. Simply use 'Ctrl-C' to kill terminal commands in linux. 

ii. Ctrl-D should be used to terminate nl correctly. 

iii. Ctrl-C is just a general way to kill #applications.


NFS Client and Server - Step by step process to configure on Debian 10 Linux System

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.



Ways to Shutdown CentOS 8

This article will guide you on different ways to shut down CentOS system. Using either of the above-discussed command line or GUI way, you can easily shutdown your #CentOS system.

To shut down the system from a terminal session, sign in or "su" to the "root" account. Then type ``/sbin/shutdown -r now''. 

It may take several moments for all processes to be terminated, and then Linux will shut down.

In #Unix and #Linux, the shutdown command can be used to turn off or reboot a computer. Only the superuser can shut the system down. 

One commonly issued form of this command is shutdown -h now , which will shut down a system immediately. 

Another one is shutdown -r now to reboot.


Different methods to uninstall programs from CentOS 8 ?

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.


Step by Step process to install and configure Zabbix monitoring server on Ubuntu ?

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.


Methods to check memory usage in CentOS 8 ?

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.


Step by step process to install and configure Odoo ERP on Ubuntu 20.04 LTS ?

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.


Step by step process to install and configure HAproxy on Ubuntu 20.04 LTS ?

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.


Step by step process to Install the latest MySQL on Debian 10 ?

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).


Step by step process to install Zimbra on Ubuntu 18.04 LTS ?

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.


Step by step process to configure Squid Proxy Server on Ubuntu 20.04 LTS ?

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.


Steps to install the latest Squid Proxy Server on Ubuntu 20.04 LTS ?

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.


Step by step process to install the latest Sublime Text editor on Ubuntu 20.04 LTS ?

This article will guide you on how to #install #Sublime Text code editor on Ubuntu 20.04 using both the #command line and the #Ubuntu #Software Center.

All Ubuntu versions have Snap enabled by default. This means you can install Notepad++ on Ubuntu from the Software Center. Once the installation completes, you can launch it from the search or by typing notepad-plus-plus into the terminal.

Sublime Text Editor is cross-platform, you can use it in #Linux, #Windows or Mac systems.


Methods to check the status of laptop battery on Ubuntu 20.04 LTS ?

This article will guide you on different methods to view detailed information on your battery using both the #command line and UI.

To check your #battery health you'll want to open the app, click on the relevant battery item in the sidebar, and double-check that you're faced with the Details tab.

1. Use upower command to check battery status from command line:

Type the following command:

$ upower -i /org/freedesktop/UPower/devices/battery_BAT0

2. Displaying #Linux Laptop Battery Status Using the apci #terminal command

The acpi command may not be installed by default so use apt-get command or yum command to install the same:

$ sudo yum install acpitool

3. Use /proc/acpi/ directory to get laptop battery info (deprecated method)

You can browse the same data by visiting /proc/acpi/ directory:

$ cd /proc/acpi/

$ ls -l


Steps to restart network services in Linux ?

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.


Steps to install XAMPP Server on Linux Mint 20 ?

This article will guide you on steps to install #XAMPP on Linux Mint 20. You will also learn the method of uninstalling XAMPP web server whenever you feel like it.

The #htdocs folder can be found in /opt/lampp/ . You can navigate to your root folder from the file manager (nautilus by default), by clicking on Other locations from the sidebar, then #Computer . From there you can find the opt folder that contains the lampp folder.

To install xampp in MX #Linux:

1. Click XAMPP for Linux. It's in the middle of the page.

2. Allow the download to complete.

3. Open #Terminal.

4. Change over to the "Downloads" directory.

5. Make the downloaded file executable.

6. Enter the installation #command.

7. Enter your password when prompted.

8. Follow the installation prompts.


Steps to create and run a Perl script in Ubuntu 20.04 LTS ?

This article will guide you on steps to #install Perl and how to create and run Perl #script using the command line on #Ubuntu 20.04. We have also discussed how to configure necessary #Perl #modules on your system.

Perl is a programming language that can be used to perform tasks that would be difficult or cumbersome on the command line. Perl is included by default with most GNU / #Linux #distributions. Usually, one invokes Perl by using a text editor to write a file and then passing it to the perl #program.

Perl has a wide range of command-line options or switches that you can use. The options are also called switches because they can turn on or turn off different behaviors. For example, the -e option lets you specify a line of code directly on the command line instead of creating a script file.

To install Perl in Linux:

1. SSH to your server.

2. Change your directory to /opt by running the below command. cd /opt.

3. Download the zipped source code available for Unix/Linux.

4. After download the zip file runs the below commands to extract and install Perl.


Methods to safely shutdown Ubuntu 20.04 LTS ?

This article will guide you on how to easily shut down your #Ubuntu 20.04 system. Here you will learn different methods will eventually cause your Ubuntu 20.04 #system to shut down.

There's nothing different in running sudo #reboot in a instance versus on your own server. This action shouldn't cause any problems. I believe the author was worried if the disk is persistent or not. Yes you can shutdown/start/reboot the instance and your data will persist.

If your system fails to boot for whatever reason, it may be useful to boot it into recovery mode. This mode just loads some basic services and drops you into command line mode. You are then logged in as root (the superuser) and can repair your system using command line tools.

To remove all #files from a directory in #Linux:

1. Open the terminal #application.

2. To delete everything in a #directory run: rm /path/to/dir/*

3. To remove all sub-directories and files: rm -r /path/to/dir/*


Steps to install Apache web server on Ubuntu 20.04 LTS ?

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.


Methods to check an available memory in Ubuntu 20.04 LTS ?

This article will guide you on how different methods of checking the available #memory in #Ubuntu 20.04. By following any of these methods, you can check the available memory along with lots of other useful memory statistics of your Ubuntu 20.04 system.

Logical Volume Manager (#LVM) is a software-based RAID-like system that lets you create "pools" of storage and add hard drive space to those pools as needed. There are lots of reasons to use it, especially in a data center or any place where storage requirements change over time.

#Linux by default tries to use RAM in order to speed up disk operations by making use of available memory for creating buffers (file system metadata) and #cache (pages with actual contents of files or block devices), helping the system to run faster because disk information is already in memory which saves I/O #operations 

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.

4. top command.

5. htop.


Step by step process to install MariaDB on Linux Mint 20 ?

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.


Steps to Install Webmin on Ubuntu 20.04 LTS ?

This article will guide you on the steps to install #Webmin in your Linux system. Webmin comes with a very simple webserver called miniserv.pl that is capable of doing all that is necessary for Webmin to run. However, it is not as fast or memory efficient as a well-developed server such as #Apache.

To modify the default port, 10000 to 10101, open the /etc/webmin/miniserv. conf file and modify line 1 and 16. Now you can access the Webmin through url with new custom port.

To Install Webmin on #Ubuntu:

1. Log in to your Ubuntu #server.

2. Issue the command sudo nano /etc/apt/sources. list.

3. Hit [CTRL][x] and save the file.

4. Add the downloaded key with the command sudo apt-key add jcameron-key. asc.

5. Update apt with the command sudo apt-get update.

6. Install Webmin with the command sudo apt-get install webmin.


How to install and configure DHCP server on Linux ?

This article will guide you on steps to install and configure the #DHCP #server in the Linux system and assign dynamic and fixed #IP addresses to the clients. It takes just a few simple steps to configure the DHCP server in a #Linux machine. Once you have configured it, it will automatically assign the assigning IP addresses and related information to each machine on the network.

The main DHCP #configuration file is /etc/dhcp/dhcpd. conf. The file is used to store the network configuration information required by DHCP #clients.

To enable DHCP or change other TCP/IP settings:

1. Select Start , then select Settings > #Network & Internet.

2. Do one of the following: For a Wi-Fi network, select Wi-Fi > Manage known networks.

3. Under IP assignment, select Edit.

4. Under Edit IP settings, select Automatic (DHCP) or Manual.

5. When you're done, select Save.


Steps to Install Samba on Ubuntu 20.04 and share files on Linux and Windows

This article will guide you on steps to #install #Samba in #Ubuntu 20.04 Linux system. We have executed all #commands and set of procedures on Ubuntu 20.04 LTS system and Windows 10. Also, We have implemented how to share folders via a local #network using Samba shares. Enjoy the benefits of Samba on your #system.

To Set up the Samba File Server on Ubuntu / #Linux:

1. Open the terminal.

2. Install samba with the following command: sudo apt-get install samba smbfs.

3. Configure samba typing: vi /etc/samba/smb.conf.

4. Set your workgroup (if necesary).

5. Set your #share folders.

6. Restart samba.

7. Create the share #folder: sudo mkdir /your-share-folder.


Steps to Create and run a Perl script in CentOS 8 ?

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.


How to use Linux command to delete the PREROUTING rule in iptables ?

This article will guide you on how to list and remove/delete iptables pretrouting chain nat rules on your #Linux based system. The -D or --delete option delete one or more rules from the selected chain. There are two versions of this #command, the rule can be specified as a number in the chain or a rule to match. One of the ways to delete #iptables #rules is by rule specification. To do so, you can run the iptables command with the -D option followed by the rule specification.


Easy way to Disable SELinux on CentOS 7 / RHEL 7 / Fedora Linux ?

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).


How To Exit Vim Text Editor Command ?

This article will guide you on how to exit #vim text editor using various options. 1. Open a new or existing file with vim filename . 2. Type i to switch into insert mode so that you can start editing the file. 3. Enter or modify the text with your file. 4. Once you're done, press the escape key Esc to get out of insert mode and back to #command mode. 5. Type :wq to save and exit your file.


How to know Ubuntu version via command line ?

This article will guide you on how to check your Ubuntu version so that you can apply patches and update versions for security and performance reasons. The Process of Checking the #Ubuntu version in the #terminal ? i. Open the terminal using "Show Applications" or use the keyboard shortcut [Ctrl] + [Alt] + [T]. ii. Type the #command "lsb_release -a" into the command line and press enter. iii. The terminal shows the Ubuntu version you're running under "Description" and "Release".


Perform SSH Installation And Configuration in CentOS

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.


Steps to save a file in Linux command line

This article will guide you on how to use the #cat #command to display or create a new file on #Linux. To save a file, you must first be in Command mode. Press Esc to enter Command mode, and then type :wq to write and quit the file. The other, quicker option is to use the keyboard shortcut ZZ to write and quit.


Install and Configure VNC on Ubuntu 20.04 - Steps to do it.

This article will guide you on the steps to set up a secured VNC server up and running on your Ubuntu 20.04 server. This will help you to manage your files, software, and settings with a user-friendly graphical interface, and you will be able to run graphical software like web browsers remotely.


How To Run a Script In Linux?

This tutorial will guide you on how to write a simple shell script and run a script in Linux operating system with help of chmod and other commands.


How to use and run bash aliases over ssh based session

This article will guide you on how to run commands and bash shell aliases on a remote machine using the ssh command.


Commands to list installed rpm packages on Linux

This article will guide you on the different commands to list all installed rpm packages on CentOS, RHEL (Red Hat Enterprise Linux), SUSE/OpenSUSE and other rpm based distros using rpm and dnf/yum command that print a list of all installed packages on your distro.


Different apt commands which you can use in Ubuntu and Debian Servers

This article will show you the different ways to use apt commands with practical examples.


Complete guide on how to modify Hostname on Ubuntu 20.04

This article will guide you on how to change your Ubuntu server hostname without restarting the system.


How to log into your Linux Server as a root user?

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


A complete guide on creating a Sudo User on Ubuntu 20.04 LTS

This article will help you to add a user account with access and privileges to run system administrator’s commands on Ubuntu 20.04 LTS systems.


Different methods of showing or hiding line numbers in Linux vi / vim text editor

This article will guide you on how to show or hide line numbers in vim / vi text editors using commands.


How to set up OpenVPN Server on CentOS 8 Server ?

In this article, you will learn how to set up an OpenVPN server on CentOS 8 Linux server.


The complete steps on how to add and create a Sudo User on CentOS Linux 8 sudoers

This article will guide you on how to add a new and existing user account to sudo in CentOS 8 by appending them to wheel group so that they can run admin commands.


How to install 389 Directory Server to serve as LDAP Server for your CentOS 8 / RHEL 8 Machine?

This article will take you through the steps on how to install 389 Directory Server LDAP Server on CentOS/RHEL 8.


How to configure DNS Server on CentOS 8?

Here, you will learn how to install and configure a DNS Server on CentOS 8 machine.


A complete guide on how to set up Static IP address on CentOS 8

This article will guide you on how to configure a Static IP address on CentOS 8.


How to install and configure CentOS 8 on VirtualBox

This article will guide you through the processes of Installing VirtualBox, CentOS 8 as a Virtual Machine (VM) on VirtualBox.


Method of installing MariaDB on CentOS 7

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.


Setting up Let's Encrypt SSL for domains hosted on an Apache web server based on CentOS 7

Let's Encrypt has gained popularity because they offer free SSL for millions of websites all over the world. They are a non-profit certificate authority run by Internet Security Research Group (ISRG) that provides X. 509 certificates for Transport Layer Security (TLS) encryption free of charge. The certificate is usually valid for 90 days after which is expires pending when it is renewed.


Easy way to free disk space on CentOS 7

The most effective method of clearing up disk space via the inbuilt resources in CentOS. This Tutorial will show you how to free up space in your CentOS machine Safely and effectively without loosing vital files.