Chapter 13. Installing kdump
Chapter 13. Installing kdump The kdump service is installed and activated by default on the new versions of RHEL 9 installations. 13.1. What is kdump kdump is a service that provides a crash dumping mechanism and generates a crash dump or a vmcore dump file. vmcore includes the contents of the system memory for analysis and troubleshooting. kdump uses the kexec system call to boot into the second kernel, capture kernel , without a reboot. This kernel captures the contents of the crashed kernel's memory and saves it into a file. The second kernel is available in a reserved part of the system memory. Important A kernel crash dump can be the only information available if a system failure occur. Therefore, operational kdump is important in mission-critical environments. Red Hat advises to regularly update and test kexec-tools in your normal kernel update cycle. This is important when you install new kernel features. If you have multiple kernels on a machine, you can enable kdump for all installed kernels or for specified kernels only. When you install kdump , the system creates a default /etc/kdump.conf file. /etc/kdump.conf includes the default minimum kdump configuration, which you can edit to customize the kdump configuration. 13.2. Installing kdump using Anaconda The Anaconda installer provides a graphical interface screen for kdump configuration during an interactive installation. You can enable kdump and reserve the required amount of memory. Procedure On the Anaconda installer, click KDUMP and enable kdump : In Kdump Memory Reservation , select Manual ` if you must customize the memory reserve. In KDUMP > Memory To Be Reserved (MB) , set the required memory reserve for kdump . = Installing kdump on the command line Installation options such as custom Kickstart installations, in some cases does not install or enable kdump by default. The following procedure helps you enable kdump in this case. Prerequisites An active RHEL subscription. A repository containing the kexec-tools package for your system CPU architecture. Fulfilled requirements for kdump configurations and targets. For details, see Supported kdump configurations and targets . Procedure Check if kdump is installed on your system: Output if the package is installed: Output if the package is not installed: Install kdump and other necessary packages:
rpm -q kexec-tools kexec-tools-2.0.22-13.el9.x86_64 package kexec-tools is not installed dnf install kexec-tools