Description and cautionsThis article describes how to configure dump for capturing memory dumps, including application memory. DetailsThe recommended text editor is nano, below is a quick tutorial on how to use it if you are using it for the first time. Quick description of nano's basic functions Configure kdump Altlinux There is no kdump-tools package in the default repository, so it has to be downloaded from the sisyphus repository: Go to https://packages.altlinux.org/en/sisyphus/srpms/kdump-tools/ In List of rpms provided by this srpm select the kdump-tools package for the required architecture (can be checked by running uname -m) Download the package from the Download link Install it by running apt-get update && apt-get install <path to the downloaded rpm> After that, follow the Debian instruction from Edit /etc/default/kdump-tools step Red Hat based distributions (tested on Fedora 38, Rocky Linux 9, Red OS) Install kexec-tools sudo dnf install kexec-toolsEdit /etc/kdump.conf. In the configuration file edit the core_collector setting: option -d should be set to 17 instead of 31 Edit /etc/default/grub. Edit GRUB_CMDLINE_LINUX, add crashkernel=256M to reserve enough RAM for the dump kernel to run, and nmi_watchdog=1, to capture a dump in case of a system hang Run sudo grub2-mkconfig -o /boot/grub2/grub.cfgReboot Enable kdump service sudo systemctl enable --now kdump.service Debian based distributions (tested on Debian, Astra CE, Alt Linux) Install kdump-tools sudo apt update && sudo apt install kdump-tools -y Edit /etc/default/kdump-tools. In the configuration file edit the MAKEDUMP_ARGS variable: option -d should be set to 17 instead of 31 Configure the bootloader In /etc/default/grub edit GRUB_CMDLINE_LINUX_DEFAULT, add nmi_watchdog=1 to capture a dump in case of a system hang In /etc/default/grub.d/kdump-tools.cfg change crashkernel value to 384M-:256M (default is 384M-:128M) Expected result: GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT crashkernel=384M-:256M" ave and run sudo update-grub SUSE Linux Install kdump sudo zypper in kdump kexec-toolsEdit /etc/sysconfig/kdump Change KDUMP_DUMPLEVEL variable to 17 Edit /etc/default/grub Edit GRUB_CMDLINE_LINUX_DEFAULT, add crashkernel=256M to reserve enough RAM for the dump kernel to run, and nmi_watchdog=1, to capture a dump in case of a system hang Update the bootloader configuration sudo grub2-mkconfig -o /boot/grub2/grub.cfgReboot Enable kdump service sudo systemctl enable --now kdump.serviceConfigure SysRq dump trigger To enable SysRq trigger, these key combinations 'kernel.sysrq = 8'(without quotes) has to be added to /etc/sysctl.conf. Reboot or run sudo sysctl --systemAfter the set up above is complete, to manually trigger a dump press Alt+SysRq, Alt+C. Alternatively: echo 8 | sudo tee /proc/sys/kernel/sysrq(Command above is only needed if kernel.sysrq is not set in /etc/sysctl.conf) echo c | sudo tee /proc/sysrq-trigger Location of the dump files may vary between different Linux versions, it is configurable in the kdump configuration file. In Debian based distributions it is set by KDUMP_COREDIR variable. In Red Hat based distributions it is set by the path setting, generally the default location is /var/crash. Make sure that the dump folder has enough free space for the dump to be written. You may search by filemask: vmcore. Related Information