.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] [--reboot]

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.

.SH "SEE ALSO"

.BR kdump.conf (5),

.BR mkdumprd (8)