The correct answer is A: ephemeral storage is non-persistent storage whose data does not need to survive Pod restarts or rescheduling. In Kubernetes, ephemeral storage typically refers to storage tied to the Pod’s lifetime—such as the container writable layer, emptyDir volumes, and other temporary storage types. When a Pod is deleted or moved to a different node, that data is generally lost.

This is different from persistent storage, which is backed by PersistentVolumes and PersistentVolumeClaims and is designed to outlive individual Pod instances. Ephemeral storage is commonly used for caches, scratch space, temporary files, and intermediate build artifacts—data that can be recreated and is not the authoritative system of record.

Option B is incorrect because “may grow dynamically” describes an allocation behavior, not the defining characteristic of ephemeral storage. Option C is incorrect because multiple consumers is about access semantics (ReadWriteMany etc.) and shared volumes, not ephemerality. Option D is incorrect because ephemeral storage is not “always provisioned locally” in a strict sense; while many ephemeral forms are local to the node, the definition is about lifecycle and persistence guarantees, not necessarily physical locality.

Operationally, ephemeral storage is an important scheduling and reliability consideration. Pods can request/limit ephemeral storage similarly to CPU/memory, and nodes can evict Pods under disk pressure. Mismanaged ephemeral storage (logs written to the container filesystem, runaway temp files) can cause node disk exhaustion and cascading failures. Best practices include shipping logs off-node, using emptyDir intentionally with size limits where supported, and using persistent volumes for state that must survive restarts.

So, ephemeral storage is best defined as storage that does not need to persist across restarts/rescheduling, matching option A.

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