I am assuming you just increased the size of a disk on a virtualization platform such as VMware or VirtualBox. Perhaps it is a SAN device. Either way, you will follow the same process. If your machine is on a SAN or it is a virtual machine running on a hypervisor that supports online resizing,… Read More »
I couldn’t find a Tomcat package in the standard repositories or EPEL, so I will walk you through installing Tomcat on CentOS 8. It is a relatively straightforward process. The latest version available at the time of writing (2019 November 23) is 9.0.29, so that is the version I will use in the examples. All… Read More »
The CentOS 8 repositories provide HAProxy version 1.8.15. You may want or need features in newer versions. Fortunately, installing HAProxy 2.0.9 (Latest stable version as of 2019 November, 21) from source is relatively straightforward. The steps to do so are: Install required packages Download the HAProxy source code Compile and install HAProxy Create an unprivileged… Read More »
This guide will walk you through setting up CentOS 8 to use an LDAP directory server for authentication. I am assuming you have a directory server up and running. If you don’t, you can follow these two guides to install and configure OpenLDAP: Install OpenLDAP From Source – CentOS 8 Configure OpenLDAP In this guide,… Read More »
With both DNF and YUM, there are three ways to remove repositories. One of the methods is specific to RHEL. If you are on a system that doesn’t have the dnf command, you can use the yum command instead. Using subscription-manager The subscription-manager program is specific to RHEL and specific to repositories maintained by Red… Read More »
Listing installed packages with dnf is straightforward. Unlike rpm, dnf also shows you the repository packages were installed from. The following example demonstrates listing all packages installed on a system. # dnf list installed Installed Packages acl.x86_64 2.2.53-1.el8 @anaconda audit.x86_64 3.0-0.10.20180831git0047a6c.el8 @anaconda audit-libs.x86_64 3.0-0.10.20180831git0047a6c.el8 @anaconda The left column displays the name of the package along… Read More »
There are a few ways to add a user to a group in Linux. I will cover two methods using the command line. Both methods require the ability to use the root account or the sudo command. Desktop environments often have GUI tools to do this. If you wish to use the GUI, check your… Read More »
To add a user to sudoers, edit the file /etc/sudoers. Many systems come with a /etc/sudoers file that gives permission to a specific group. If your /etc/sudoers has a line that looks like one of these, you can allow a user to use sudo by adding the user to that group. %sudo ALL=(ALL:ALL) ALL %sudo… Read More »
To create a symbolic link on a UNIX or Linux system, use the ln command with the -s option. You may see or hear a symbolic link referred to as a soft link or symlink. All three terms mean the same thing. Here is an example: $ ln -s file_name link_name $ ls -l total… Read More »
On Linux and UNIX systems, there are two types of links. Both types are created with the ln command. They function similarly but have some differences. First, you need to understand a little bit about how filesystems work. Filesystems store meta data such as permissions, modification times, and the location of the file’s data on… Read More »