Certified Kubernetes Administrator (CKA) Practice Test

HostPath volume types support the ReadWriteOnce access mode. This mode allows a single node to mount the volume as read-write. A hostPath volume mounts a file or directory from the host node's filesystem into a Pod, meaning that only one Pod on that specific node can write to the mounted path at any given time.

Using ReadWriteOnce ensures that while the Pod can write to the mounted path, there are no concurrent writes or reads from multiple nodes, as this could lead to data corruption or inconsistencies. This characteristic aligns with how hostPath functions, since it directly reflects a physical path on the node's filesystem.

Other access modes, such as ReadWriteMany, which allows multiple nodes to mount the volume as read-write simultaneously, or ReadOnlyMany, which allows multiple nodes to mount the volume as read-only, are not compatible with hostPath volumes. Furthermore, ReadWriteOncePod is a higher-level abstraction that ensures a volume can only be mounted by one Pod at a time but does not specifically apply to hostPath volumes. Thus, the most appropriate mode for hostPath volumes is ReadWriteOnce.