Can you explain what is meant by Kubernetes Storage and how it is used in clusters?

Kubernetes Storage is a mechanism for managing data and its storage within a Kubernetes cluster. It allows containers to save and use data outside their lifecycle, ensuring persistence and accessibility.

Key concepts:

• Volume — an abstraction for data storage that is mounted into a container. Unlike the container's filesystem, a volume persists longer than the container itself.
• PersistentVolume (PV) — a cluster resource representing physical storage (e.g., disk, network storage).
• PersistentVolumeClaim (PVC) — a user request for a specific amount and type of storage.

Usage:

1. An administrator creates a PV, describing available storage.
2. A developer creates a PVC, specifying the required size and parameters.
3. Kubernetes binds the PVC to an appropriate PV.
4. Containers in a Pod mount the PVC as a volume to work with data.

Example PVC manifest:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: my-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi

Thus, Kubernetes Storage provides persistent data storage necessary for stateful applications in a cluster.