PersistentVolume

PersistentVolume is a Kubernetes API object that represents a piece of storage in the cluster. It is cluster-scoped and exists beyond the life of any individual Pod. A PV can be backed by various storage systems, including local disks, NFS, iSCSI, or cloud-provider volumes such as AWS EBS, GCE Persistent Disk, or Azure Disk. The data in a PV can persist across Pod restarts and rescheduling, depending on its reclaim policy and backing storage.

A PersistentVolumeClaim is a request for storage by a user or application. A PVC specifies requirements such as size and allowed access modes (for example, ReadWriteOnce, ReadOnlyMany, ReadWriteMany). The control plane binds a PVC to a suitable PV that satisfies these requirements. Once bound, a Pod can mount the storage by referencing the claim in its volume specification, allowing consistent storage access for the lifetime of the Pod.

Dynamic provisioning enables on-demand PV creation. When a PVC requests storage with a StorageClass that supports dynamic provisioning, the cluster automatically provisions a new PV using the configured provisioner, abstracting away manual PV creation.

PV lifecycle is influenced by its reclaim policy, which can be Delete or Retain. Delete removes the underlying storage when the PVC is deleted (where supported), while Retain keeps the PV and requires manual cleanup. The PV also has phases, including Available, Bound, Released, and Failed, reflecting its current state within the cluster.

Key fields in a PV include capacity, accessModes, persistentVolumeReclaimPolicy, storageClassName, and claimRef linking it to its PVC. PersistentVolume thus provides a stable, cluster-wide abstraction for storage that decouples storage management from pod scheduling.