140da74a34
Rewrite kdumpctl reset-crashkernel KERNEL_PATH as
kdumpctl reset-crashkernel [--fadump=[on|off|nocma]] [--kernel=path_to_kernel] [--reboot]
This interface would reset a specific kernel to the default crashkernel value
given the kernel path. And it also supports grubby's syntax so there are the
following special cases,
- if --kernel not specified,
- use KDUMP_KERNELVER if it's defined in /etc/sysconfig/kdump
- otherwise use current running kernel, i.e. `uname -r`
- if --kernel=DEFAULT, the default boot kernel is chosen
- if --kernel=ALL, all kernels would have its crashkernel reset to the
default value and the /etc/default/grub is updated as well
--fadump=[on|off|nocma] toggles fadump on/off for the kernel provided
in KERNEL_PATH. If --fadump is omitted, the dump mode is determined by
parsing the kernel command line for the kernel(s) to update.
CoreOS/Atomic/Silverblue needs to be treated as a special case because,
- "rpm-ostree kargs" is used to manage kernel command line parameters
so --kernel doesn't make sense and there is no need to find current
running kernel
- "rpm-ostree kargs" itself would prompt the user to reboot the system
after modify the kernel command line parameter
- POWER is not supported so we can assume the dump mode is always kdump
This interface will also be called by kexec-tools RPM scriptlets [1]
to reset crashkernel.
Note the support of crashkenrel.default is dropped.
[1] https://docs.fedoraproject.org/en-US/packaging-guidelines/Scriptlets/
Reviewed-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
70 lines
2.0 KiB
Groff
70 lines
2.0 KiB
Groff
.TH KDUMPCTL 8 2015-07-13 kexec-tools
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.SH NAME
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kdumpctl \- control interface for kdump
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.SH SYNOPSIS
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.B kdumpctl
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.I COMMAND
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.SH DESCRIPTION
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.B kdumpctl
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is used to check or control the kdump service.
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In most cases, you should use
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.B systemctl
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to start / stop / enable kdump service instead. However,
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.B kdumpctl
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provides more details for debug and a helper to setup ssh key authentication.
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.SH COMMANDS
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.TP
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.I start
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Start the service.
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.TP
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.I stop
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Stop the service.
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.TP
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.I status
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Prints the current status of kdump service.
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It returns non-zero value if kdump is not operational.
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.TP
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.I restart
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Is equal to
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.I start; stop
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.TP
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.I reload
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reload crash kernel image and initramfs without triggering a rebuild.
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.TP
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.I rebuild
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rebuild the crash kernel initramfs.
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.TP
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.I propagate
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Helps to setup key authentication for ssh storage since it's
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impossible to use password authentication during kdump.
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.TP
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.I showmem
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Prints the size of reserved memory for crash kernel in megabytes.
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.TP
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.I estimate
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Estimate a suitable crashkernel value for current machine. This is a
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best-effort estimate. It will print a recommanded crashkernel value
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based on current kdump setup, and list some details of memory usage.
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.TP
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.I reset-crashkernel [--kernel=path_to_kernel] [--reboot]
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Reset crashkernel to default value recommended by kexec-tools. If no kernel
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is specified, will reset KDUMP_KERNELVER if it's defined in /etc/sysconfig/kdump
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or current running kernel's crashkernel value if KDUMP_KERNELVER is empty. You can
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also specify --kernel=ALL and --kernel=DEFAULT which have the same meaning as
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grubby's kernel-path=ALL and kernel-path=DEFAULT. ppc64le supports FADump and
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supports an additonal [--fadump=[on|off|nocma]] parameter to toggle FADump
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on/off.
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Note: The memory requirements for kdump varies heavily depending on the
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used hardware and system configuration. Thus the recommended
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crashkernel might not work for your specific setup. Please test if
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kdump works after resetting the crashkernel value.
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.SH "SEE ALSO"
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.BR kdump.conf (5),
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.BR mkdumprd (8)
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