cadvisor : Factory "docker" was unable to handle container "/system.slice/kdump.service"
kdump.service is a system service, not a Docker container. You can read more on it here. What you see in logs is debug information, telling you that cAdvisor has no handler for kernel dump service. This is not an error and it is only visible because you've increased verbosity ("-v=4" in your command:). You can either decrease verbosity or simply ignore these messages.