CompTIA Linux+ XK0-006 (V8) Practice Question

The ctr CLI shows resources that exist inside a specific containerd namespace. If no namespace is specified, ctr defaults to the namespace named "default", which Kubernetes does not use. Instead, the kubelet stores all of its container objects in the namespace called "k8s.io". Supplying the -n k8s.io (or --namespace k8s.io) option therefore targets the correct namespace, and the containers list sub-command then prints the container records associated with the running Pods.

The other commands are wrong for these reasons:

• Using --namespace default still points to the empty default namespace.
• The moby namespace is used by Docker, not by Kubernetes.
• --all-namespaces is not a valid flag for ctr, so the command will fail.