The purpose of this tutorial is to show how to fix the RHEL7 User Not In Sudoers File Error on all major Linux distributions. When trying to execute Linux commands with root privileges via the sudo command, you will receive an error message if the current user is not in the sudoers file. This is a security feature on Linux systems to stop ordinary users from esclating their commands to administrator privileges.
Flatpak is a package manager that is available for installation on CentOS Linux and all other major Linux distros. Flatpak offers CentOS users an alternative to the official repos and default dnf package manager as a source of software installation. Many applications available in Flatpak currently do not reside in official CentOS repos, making this a big benefit of installing Flatpak.
The purpose of this tutorial is to show how to check the CentOS version of your Linux system. It’s possible to do this from either command line or GUI, so you can use whichever method is more convenient for you. Classic CentOS is nearing its end of life and will be replaced by CentOS Stream. Knowing your CentOS version will give you some insight into how long your system will continue to be supported.
firewalld is the default firewall on Red Hat Enterprise Linux, and it’s enabled by default, but it’s possible to disable the firewall on Redhat, and you’ll also see how to check firewall status in Linux. Normally, there should not be a need to disable the firewall, but it may be quite handy for testing purposes or other scenarios. In this tutorial, you’ll see how to check the status of firewalld, enable or disable the service from starting automatically upon system boot, and how to stop or start the firewalld service in RHEL.
Files with the .RPM extension are software packages intended for installation on Red Hat Enterprise Linux or one of its derivative Linux distributions, such as CentOS, AlmaLinux, Rocky Linux, or Fedora. When you install software by using an RPM file, your system may need to install dependencies for it to run correctly. This is common behavior for the dnf package manager as well, so you may already be familiar with package dependencies. In this tutorial, we will show you how to check the package dependencies for an RPM file on RHEL and similar distros.
The SSH protocol operates on port 22 by default. In order to accept incoming connections on your Red Hat 7 Linux SSH server, you will need to ensure that port 22 is allowed through the firewall. This will involve opening the port in firewalld, the default firewall interface for Red Hat.
By default, the Red Hat Enterprise Linux distribution sports the GNOME desktop environment, or no GUI at all. If you would like to change things up and install KDE Plasma instead, the GUI can be downloaded and installed directly from Red Hat’s package repositories.
The conventional way used to change the runlevel with /etc/inittab has become obsolete with Red Hat Enterprise Linux version 7. As a result, any Linux system using systemd system management daemon now relies on the systemctl command to change runlevel – or, to be more precise, to change the target. Therefore any edits to the /etc/inittab file will not take effect on RHEL 7.
The hostname of your Red Hat Enterprise Linux system is important because it’s used to identify the device on a network. The hostname is also shown in other prominent places, such as in the terminal prompt. If you have not bothered to change the hostname yet, your system probably bears the default localhost.localdomain name, which is not very helpful.
When running an Apache web server on Red Hat Enterprise Linux, you may encounter the error AH00557: httpd: apr_sockaddr_info_get() failed or AH00558: httpd: Could not reliably determine the server's fully qualified domain name when trying to start the service. In this tutorial, we will look into the cause of this error and give you a solution for fixing it.
You may receive a There are no enabled repos error message when trying to install system updates on a fresh Red Hat Linux install. This occurs when you have not enabled your RHEL subscription. In this tutorial, we will take you through the step by step instructions to register your RHEL subscription, enable the package manager, and finally install updates and remedy the error message for good.
The purpose of this tutorial is to show how to find the system IP address, public IP address, default gateway, and DNS servers on CentOS Linux and Red Hat Linux. This can be done from both command line and GUI. We will cover the step by step instructions for both methods below.