kdumpctl is used to check or control the kdump service. In most cases, you should use systemctl to start / stop / enable kdump service instead. However, kdumpctl provides more details for debug and a helper to setup ssh key authentication.
Start the service.
Stop the service.
Prints the current status of kdump service. It returns non-zero value if kdump is not operational.
Is equal to start; stop
reload crash kernel image and initramfs without triggering a rebuild.
rebuild the crash kernel initramfs.
Helps to setup key authentication for ssh storage since it's impossible to use password authentication during kdump.
Prints the size of reserved memory for crash kernel in megabytes.