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.
Redhat / CentOS / AlmaLinux
There are no enabled repositories RHEL solution
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.
Check IP Address CentOS/RHEL
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.
How to disable SElinux on CentOS 7
SELinux, which stands for Security Enhanced Linux, is an extra layer of security control built for Linux systems. The original version of SELinux was developed by the NSA. Other key contributors include Red Hat, which has enabled it by default in their own RHEL and its derivative Linux distributions, including CentOS 7.
How to auto login on CentOS
The purpose of this tutorial is to enable auto login on GNOME GUI and the KDE Plasma desktop environment on CentOS Linux system. If you are using CentOS and getting tired of needing to provide your password every time your computer boots up, or goes back to the lock screen, then enabling auto login will save you some time and frustration.
How to install Gnome and start GUI in Redhat Linux
This article will answer the following questions: How to start GUI in Redhat Linux. GNOME is the default desktop environment on Red Hat Enterprise Linux, but only if you opt for the full installation of the operating system. Other installations don’t include any GUI by default. If you’ve chosen a minimal install but don’t want to be limited to just the command line, you can install the GNOME desktop environment in a few simple commands.
How to open http port 80 in Redhat Linux using firewall-cmd
This article will provide you with an information on how to open port in Redhat Linux, and more specifically we will be talking about the HTTP port 80. firewalld is the default firewall program that comes pre-installed on Red Hat Enterprise Linux 7 and 8. By default, the firewall is turned on, meaning that a very limited number of services are able to receive incoming traffic.
How to start httpd service in RHEL Linux
The purpose of this guide is to show the steps to install Apache web server on Red Hat Enterprise Linux versions 7 and 8. Then, we will show how to start httpd service in RHEL.
RHEL default gateway configuration
The default gateway is an essential part of computer networking. When a computer attempts to communicate with another device, it will send packets to the default gateway. The default gateway, which is usually a router, will then direct the packets where they need to go.
Configure logrotate on Redhat Linux
Logrotate is a utility designed for administrators who manage servers that produce a high volume of log files. It helps them save some disk space, as well as to avoid a potential risk of making a system unresponsive due to the lack of disk space.
How to query packages information with the rpm package manager
RPM is the recursive acronym for RPM Package Manager: it is the default low level package manager in some of the most famous and most used Linux distributions, such as Fedora, Red Hat Enterprise Linux, CentOS, OpenSUSE and their derivatives. The software, as you can expect, is free and open source; when invoked with the -q
option it can be used to query packages to retrieve specific information, such as dependencies, recommendations, files etc. In this tutorial we learn how to perform such queries.
In this tutorial you will learn:
- How to run rpm in “query” mode
- How to obtain general information about a package
- How to read a package changelog
- How to list the files provided by a package
- How to list the scripts used by a package
- How to list a package dependencies and recommendations
- How to list packages rendered obsolete by an rpm