kexec-tools/kdumpctl.8
Philipp Rudo b4b57ca36b kdumpctl: deprecate --reboot for reset-creashkernel
Resolves: RHEL-49555
Upstream: rhkdump/kdump-utils
Conflicts: Slightly changed warning message to reference RHEL11 rather
           than "the future".

commit ca6da9b484e7995d8f3ee7e74dd871ee8919e409
Author: Philipp Rudo <prudo@redhat.com>
Date:   Wed Oct 2 15:26:34 2024 +0200

    kdumpctl: deprecate --reboot for reset-creashkernel

    The --reboot option for reset-crashkernel causes quite some confusion.
    Especially, there are different expectations when --reboot shall reboot
    the system. The current code only reboots the system when the
    crashkernel parameter was updated during this run. But there are other
    opinions, that --reboot shall also reboot the system if a previous run
    of `kdumpctl reset-crashkernel` updated the crashkernel parameter and no
    reboot occurred yet. While possible this would add extra complexity to
    the code. Neither the confusion nor the extra complexity are justified,
    given that --reboot only replaces a single additional command for the
    user.

    Thus deprecate the --reboot option so it can be removed later on.

    Signed-off-by: Philipp Rudo <prudo@redhat.com>

Signed-off-by: Philipp Rudo <prudo@redhat.com>
2025-09-17 15:39:07 +02:00

82 lines
2.6 KiB
Groff

.TH KDUMPCTL 8 2015-07-13 kexec-tools
.SH NAME
kdumpctl \- control interface for kdump
.SH SYNOPSIS
.B kdumpctl
.I COMMAND
.SH DESCRIPTION
.B kdumpctl
is used to check or control the kdump service.
In most cases, you should use
.B systemctl
to start / stop / enable kdump service instead. However,
.B kdumpctl
provides more details for debugging and a helper to set up ssh key authentication.
.SH COMMANDS
.TP
.I start
Start the service.
.TP
.I stop
Stop the service.
.TP
.I status
Prints the current status of kdump service.
It returns a non-zero value if kdump is not operational.
.TP
.I restart
Is equal to
.I start; stop
.TP
.I reload
reload the crash kernel image and initramfs without triggering a rebuild.
.TP
.I rebuild
rebuild the crash kernel initramfs.
.TP
.I propagate
Helps to setup key authentication for ssh storage since it's
impossible to use password authentication during kdump.
.TP
.I showmem
Prints the size of reserved memory for the crash kernel in megabytes.
.TP
.I estimate
Estimate a suitable crashkernel value for the current machine. This is a
best-effort estimate. It will print a recommended crashkernel value
based on the current kdump setup, and list some details of memory usage.
.TP
.I get-default-crashkernel
Return the default crashkernel value provided by kexec-tools.
.TP
.I reset-crashkernel [--kernel=path_to_kernel]
Reset crashkernel to default value recommended by kexec-tools. If no kernel
is specified, will reset KDUMP_KERNELVER if it's defined in /etc/sysconfig/kdump
or the current running kernel's crashkernel value if KDUMP_KERNELVER is empty. You can
also specify --kernel=ALL and --kernel=DEFAULT which have the same meaning as
grubby's kernel-path=ALL and kernel-path=DEFAULT. ppc64le supports FADump and
supports an additional [--fadump=[on|off|nocma]] parameter to toggle FADump
on/off.
Note: The memory requirements for kdump varies heavily depending on the
used hardware and system configuration. Thus the recommended
crashkernel might not work for your specific setup. Please test if
kdump works after resetting the crashkernel value.
.TP
.I test [--force]
Test the kdump by actually trigger the system crash & dump, and check if a
vmcore can really be generated successfully based on current config and
environment. After system reboot back to normal, check the test result
by "kdumpctl status". Note, fadump is not supported.
If the optional parameter [--force] is provided, there will be no confirmation
before triggering the system crash. Dangerous though, this option is meant
for automation testing.
.SH "SEE ALSO"
.BR kdump.conf (5),
.BR mkdumprd (8)