Redhat Linux

Configure default KVM virtual storage on Redhat Linux

Objective The default KVM virtual storage location is /var/lib/libvirt/images meaning, that any new virtual machines created via Virtual Machine Manager will be stored within this location. The objective of this guide is to configure another default KVM virtual storage directory location. Operating System and Software Versions Operating System: - Redhat 7.3 Software: - libvirtd (libvirt) 2.0.0 Requirements Privileged access to your Redhat Linux installation is required. Difficulty EASY...
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How to configure Virtualization on Redhat Linux

Objective The following quick guide will help you setup Redhat Enterprise Linux server as a virtualization host using KVM. Operating System and Software Versions Operating System: - Red Hat 7 Requirements Privileged access to RHEL installation will be required. Difficulty EASY Conventions
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How to disable default Apache welcome page on Redhat Linux

Objective The objective is to disable the default Apache (httpd) welcome page on Redhat Linux Operating System and Software Versions Operating System: - Red Hat Enterprise Linux Server 7.3 (Maipo) Software: - Apache/2.4.6 (Red Hat Enterprise Linux) Requirements Privileged access to your RHEL server system will be required. Difficulty EASY Conventions
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Configure local network Redhat package repository over HTTP with Apache

Objective The objective is to configure network Redhat package repository accessible via HTTP protocol. This guide uses Apache webserver as a means to provide HTTP access to the local package repository. Operating System and Software Versions Operating System: - Red Hat Enterprise Linux Server 7.3 (Maipo) Software: - Apache/2.4.6 (Red Hat Enterprise Linux) Requirements Privileged access to your RHEL server system will be required. Difficulty EASY Conventions
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How to force text mode installation of Redhat Linux

Objective In case you have troubles with GUI RHEL installation, Redhat also offers text bases solution. Operating System and Software Versions Operating System: - Redhat Linux 7.3 Requirements Redhat Linux bootable CD/DVD or USB media. Difficulty EASY Conventions
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Configure local network Redhat package repository with vsftpd

Objective The objective is to configure network Redhat package repository accessible via FTP protocol. This guide uses vsftpd as a means to provide FTP access to the package repository. Operating System and Software Versions Operating System: - Red Hat Enterprise Linux Server 7.3 (Maipo) Software: - vsftpd: version 3.0.2 Requirements Privileged access to your RHEL server system will be required. Difficulty EASY Conventions
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How to check Redhat version

Objective The objective of this guide is to provide you with some hints on how to check system version of your Redhat Enterprise Linux (RHEL). There exist multiple ways on how to check the system version, however, depending on your system configuration, not all examples described below may be suitable. For a CentOS specific guide visit How to check CentOS version guide. Requirements Privileged access to to your RHEL system may be required. Difficulty EASY Conventions
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Docker installation on RHEL 7 Linux

Objective The objective is to install Docker engine on Redhat 7 Linux using native docker script. Requirements Internet connection as well as a privileged access to your Redhat 7 Linux is required. Difficulty EASY Conventions # - requires given command to be executed with root privileges either directly as a root user or by use of sudo command $ - given command to be executed as a regular non-privileged user Instructions Install docker Installation of docker using a native docker script is one...
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Unbound cache-only DNS server setup on RHEL 7 Linux

Introduction Unbound is a validating, recursive, and caching DNS server. Having said that, Unbound DNS server cannot be used as an authoritative DNS server, which means it cannot be used to host custom domain name records. As a result, if your goal is to build a cache-only or forwarding DNS server, Unbound may be your preferred choice, as it does just that and it does it well. Objective The objective is to provide quick and easy to follow installation and configuration guide for the Unbound...
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How to disable last login message on RHEL Linux

Objective The objective is to permanently disable a last login message after user terminal or ssh login on Redhat Linux. Example: $ ssh linuxconfig@10.1.1.45 linuxconfig@10.1.1.45's password: Last login: Tue Dec 6 11:23:11 2016 from 10.1.1.3 Requirements Privileged access to your Redhat Linux server. Difficulty EASY Conventions # - requires given command to be executed with root privileges either directly as a root user or by use of sudo command $ - given command to be executed as a regular...
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RHEL7 - user is not in the sudoers file error

Objective By default the regular user does not have an ability to execute commands with root privileges. As a result the following message will appear: $ sudo -i [sudo] password for linuxconfig: linuxconfig is not in the sudoers file. This incident will be reported. The objective is to gain a superuser ( root ) access on Redhat 7 Linux server using sudo command. Requirements Privileged root access to your Redhat 7 Linux server installation. Difficulty EASY Conventions # - requires given...
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How to mount CD/DVD ROM on RHEL 7 Linux

Objective The objective is to mount a CD/DVD block device with ISO 9660 disk image/media. Requirements Privileged access to your Redhat 7 system. Difficulty EASY Conventions # - requires given command to be executed with root privileges either directly as a root user or by use of sudo command $ - given command to be executed as a regular non-privileged user Instructions Locate Block device First we need to find a correct CD/DVD block device. To do this execute a command blkid : # blkid...
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How to reset the root password in RHEL7/CentOS7/Scientific Linux 7- based systems

Objective Resetting the root password in RHEL7/CentOS7/Scientific Linux 7 Requirements RHEL7 / CentOS7 / Scientific Linux 7 Difficulty MODERATE Instructions Things have changed in the RHEL7 world and so has the preferred way of resetting the root password. Although the old way of interrupting the boot process (init=/bin/bash) still works, it is no longer bulletproof and recommended. 'Systemd' uses 'rd.break' to interrupt the boot. Let's have a quick walk through the whole procedure.
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Creating a Redhat package repository

Introduction If your Redhat server is not connected to the official RHN repositories, you will need to configure your own private repository which you can later use to install packages. The procedure of creating a Redhat repository is quite simple task. In this article we will show you how to create a local file Redhat repository as well as remote HTTP repository. Using Official Redhat DVD as repository After default installation and without registering your server to official RHN repositories...
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How to establish PPTP VPN client connection on CENTOS/RHEL 7 Linux

This guide will discuss a procedure on how to connect/establish a VPN connection using PPTP protocol on CentOS 7 or Redhat 7 Linux the non-GUI way. Below you can find connection details which will be used as an example. Replace the bellow PPTP VPN information to align with your PPTP VPN server settings: Connection name: linuxconfig ( can be any descriptive name ) VPN connetion type: PPTP PPTP VPN server IP or domain: 123.123.1.1 CHAP Username: admin CHAP User password: 00000000 Configuration...
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Persistent/Automatic after reboot kernel module loading on CentOS/Redhat Linux

This config will describe a procedure on how to persistently load kernel modules during a boot time on CentOS or Redhat Linux system. In the below commands will use nf_conntrack_pptp as a sample module. Replace the name of this module with a module name you wish to load. First, create a script within /etc/sysconfig/modules/ directory with a file extension modules . Where the name of the script can be any name of your choice. In our case the script will be called nf_conntrack_pptp.modules....
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How to set the primary display on CentOS/RHEL 7 with dual monitors and GNOME

This article will describe a way on how to change/set a primary display on CentOS/RHEL 7 with dual monitors and GNOME. The easiest and perhaps recommended way is to use GUI and navigate to Applications-> System Tools-> Settings-> Displays . The current primary screen is highlighted by a black top bar. To change you primary display simply drag-n-drop the black top bar from one screen to another: . Another alternative is to you command line tool xrandr . First get all your connected screens: $...
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How to enable EPEL repository on RHEL 7 without a current Red Hat Subscription

If you currently do not hold a Red Hat Subscription and yet you need to enable EPEL ( Extra Packages for Enterprise Linux ) repository on your RHEL 7 Linux you need to download and install following file directly from Fedora project: epel-release-7-5.noarch.rpm
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Configure firewall to enable NTP port 123 on RHEL7 Linux

Once you configure NTPD service on your RHEL7 linux you will need to allow traffic through the firewall on port 123. Te following command will enable all public traffic on UDP port 123: # firewall-cmd --zone=public --add-port=123/udp --permanent success
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Working with systemd targets on RHEL7 Linux beginners cheatsheet

Below you can find a list of most frequently used commands in association with systemd targets: List current active default target # systemctl get-default List all active systemd targets: # systemctl list-units --type target
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