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.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 debugging and a helper to set up 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 a 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 the 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 the 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 the current machine. This is a
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best-effort estimate. It will print a recommended crashkernel value
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based on the current kdump setup, and list some details of memory usage.
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.TP
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.I get-default-crashkernel
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Return the default crashkernel value provided by kexec-tools.
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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 the 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 additional [--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)