From d3dba4cbc369143e20a1a4a09f5f42cc32382332 Mon Sep 17 00:00:00 2001 From: Coiby Xu Date: May 17 2022 09:23:10 +0000 Subject: update crashkernel-howto Resolves: bz2073676 Upstream: Fedora Conflict: None commit 683ff878213ea2a58971902f90f9dd77d4e64b8f Author: Coiby Xu Date: Mon Apr 18 15:54:53 2022 +0800 update crashkernel-howto 1. clean up left crashkernel.default 2. fix a few typos and grammar mistakes 3. ask the users to refer to `man kdumpctl` for reset-crashkernel Philipp Rudo Signed-off-by: Coiby Xu Signed-off-by: Coiby Xu --- diff --git a/crashkernel-howto.txt b/crashkernel-howto.txt index 1ba79ab..94f4e52 100644 --- a/crashkernel-howto.txt +++ b/crashkernel-howto.txt @@ -37,10 +37,10 @@ Users can override the value during Anaconda installation manually. Auto update of crashkernel boot parameter ========================================= -A new release of kexec-tools could update the default crashkernel value. -By default, kexec-tools would reset crashkernel to the new default value if it -detects old default crashkernel value is used by installed kernels. If you don't -want kexec-tools to update the old default crashkernel to the new default +A new release of kexec-tools could update the default crashkernel value. By +default, kexec-tools would reset crashkernel to the new default value if it +detects the old default crashkernel value is used by installed kernels. If you +don't want kexec-tools to update the old default crashkernel to the new default crashkernel, you can change auto_reset_crashkernel to no in kdump.conf. Supported Bootloaders @@ -67,19 +67,18 @@ value properly, `kdumpctl` also provides a sub-command: `kdumpctl reset-crashkernel [--kernel=path_to_kernel] [--reboot]` -This command will read from the `crashkernel.default` file and reset -bootloader's kernel cmdline to the default value. It will also update bootloader -config if the bootloader has a standalone config file. User will have to reboot -the machine after this command to make it take effect if --reboot is not specified. -For ppc64le, an optional "[--fadump=[on|off|nocma]]" can also be specified to toggle -FADump on/off. +This command will reset the bootloader's kernel cmdline to the default value. +It will also update bootloader config if the bootloader has a standalone config +file. User will have to reboot the machine after this command to make it take +effect if --reboot is not specified. For more details, please refer to the +reset-crashkernel command in `man kdumpctl`. Reset manually -------------- To reset the crashkernel value manually, it's recommended to use utils like `grubby`. A one liner script for resetting `crashkernel=` value of all installed -kernels to current boot kernel's crashkernel.default` is: +kernels to the default value is: grubby --update-kernel ALL --args "crashkernel=$(kdumpctl get-default-crashkernel)" @@ -98,7 +97,7 @@ triggering kdump: The output will be like this: ``` - Encrypted kdump target requires extra memory, assuming using the keyslot with minimun memory requirement + Encrypted kdump target requires extra memory, assuming using the keyslot with minimum memory requirement Reserved crashkernel: 256M Recommended crashkernel: 655M