Red Hat SummitChapter 3. Installing kdump
The kdump service is installed and activated by default on the new versions of RHEL 10 installations.
3.1. What is kdump
kdump provides a crash dumping mechanism that generates a vmcore file for analysis. By using the kexec system call, it boots into a reserved capture kernel without a reboot to save the crashed kernel’s memory to a file.
A kernel crash dump can be the only information available if a system failure occur. Therefore, operational kdump is important in mission-critical environments. You must regularly update and test kexec-tools, kdump-utils, and makedumpfile packages 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.
3.2. 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.
3.3. Installing kdump on the command line
Custom installation options such as Kickstart installations might not install or enable kdump by default. You can manually install and enable kdump on the command line when needed.
Prerequisites
- An active RHEL subscription.
-
A repository containing the
kexec-toolspackage for your system CPU architecture. -
Fulfilled requirements for
kdumpconfigurations and targets. For details, see Supported kdump configurations and targets.
Procedure
Check if
kdumpis installed on your system:# rpm -q kexec-toolsOutput if the package is installed:
kexec-tools-2.0.29-21.el10.x86_64Output if the package is not installed:
package kexec-tools is not installedInstall
kdumpand other necessary packages:# dnf install kexec-tools
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