update crashkernel-howto

Resolves: bz2073676
Upstream: Fedora
Conflict: None

commit 683ff87821
Author: Coiby Xu <coxu@redhat.com>
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 <prudo@redhat.com>

    Signed-off-by: Coiby Xu <coxu@redhat.com>

Signed-off-by: Coiby Xu <coxu@redhat.com>
This commit is contained in:
Coiby Xu 2022-05-11 10:25:56 +08:00 committed by Tao Liu
parent 0e3a77330e
commit d3dba4cbc3

View File

@ -37,10 +37,10 @@ Users can override the value during Anaconda installation manually.
Auto update of crashkernel boot parameter Auto update of crashkernel boot parameter
========================================= =========================================
A new release of kexec-tools could update the default crashkernel value. A new release of kexec-tools could update the default crashkernel value. By
By default, kexec-tools would reset crashkernel to the new default value if it 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 detects the old default crashkernel value is used by installed kernels. If you
want kexec-tools to update the old default crashkernel to the new default 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. crashkernel, you can change auto_reset_crashkernel to no in kdump.conf.
Supported Bootloaders Supported Bootloaders
@ -67,19 +67,18 @@ value properly, `kdumpctl` also provides a sub-command:
`kdumpctl reset-crashkernel [--kernel=path_to_kernel] [--reboot]` `kdumpctl reset-crashkernel [--kernel=path_to_kernel] [--reboot]`
This command will read from the `crashkernel.default` file and reset This command will reset the bootloader's kernel cmdline to the default value.
bootloader's kernel cmdline to the default value. It will also update bootloader It will also update bootloader config if the bootloader has a standalone config
config if the bootloader has a standalone config file. User will have to reboot file. User will have to reboot the machine after this command to make it take
the machine after this command to make it take effect if --reboot is not specified. effect if --reboot is not specified. For more details, please refer to the
For ppc64le, an optional "[--fadump=[on|off|nocma]]" can also be specified to toggle reset-crashkernel command in `man kdumpctl`.
FADump on/off.
Reset manually Reset manually
-------------- --------------
To reset the crashkernel value manually, it's recommended to use utils like 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 `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=$(kdumpctl get-default-crashkernel)" grubby --update-kernel ALL --args "crashkernel=$(kdumpctl get-default-crashkernel)"
@ -98,7 +97,7 @@ triggering kdump:
The output will be like this: 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 Reserved crashkernel: 256M
Recommended crashkernel: 655M Recommended crashkernel: 655M