Update docs with subpath limitation (#7533)

docs/tasks/configure-pod-container/configure-pod-configmap.md

@@ -476,6 +476,11 @@ basis. The [Secrets](/docs/concepts/configuration/secret/#using-secrets-as-files
 
 When a ConfigMap already being consumed in a volume is updated, projected keys are eventually updated as well. Kubelet is checking whether the mounted ConfigMap is fresh on every periodic sync. However, it is using its local ttl-based cache for getting the current value of the ConfigMap. As a result, the total delay from the moment when the ConfigMap is updated to the moment when new keys are projected to the pod can be as long as kubelet sync period + ttl of ConfigMaps cache in kubelet.
 
+**Note:** A container using a ConfigMap as a
+[subPath](/docs/concepts/storage/volumes/#using-subpath) volume will not receive
+ConfigMap updates.
+{: .note}
+
 {% endcapture %}
 
 {% capture discussion %}

docs/tasks/inject-data-application/downward-api-volume-expose-pod-information.md

@@ -135,6 +135,11 @@ written to a new temporary directory, and the `..data` symlink is updated
 atomically using
 [rename(2)](http://man7.org/linux/man-pages/man2/rename.2.html).
 
+**Note:** A container using Downward API as a
+[subPath](/docs/concepts/storage/volumes/#using-subpath) volume mount will not
+receive Downward API updates.
+{: .note}
+
 Exit the shell:
 
 ```shell