A PersistentVolume (PV) is a piece of storage in a Kubernetes cluster that has been provisioned for use by applications running in the cluster. Think of it as a virtual representation of actual physical or cloud-based storage that's been made available to your Kubernetes environment.
PersistentVolumes have several defining characteristics that make them essential to Kubernetes storage management:
Cluster-wide resource: Unlike many Kubernetes resources that exist within a namespace, PVs exist at the cluster level and can potentially be used by any application in any namespace (depending on access controls and binding status).
Storage abstraction: PVs abstract the details of how storage is implemented (whether it's AWS EBS, Google Persistent Disk, NFS, etc.) from the applications that use the storage. This provides a consistent interface for applications regardless of the underlying storage provider.
Independent lifecycle: A PV's existence continues regardless of what happens to the pods that may use it. When a pod is deleted, the PV continues to exist according to its configured reclaim policy.
Storage capacity: Each PV has a specific storage capacity (e.g., 10Gi, 500Gi) that defines how much data it can hold.
Access modes: PVs support different access modes, such as ReadWriteOnce (usable by a single node), ReadOnlyMany (readable by many nodes), or ReadWriteMany (readable and writable by many nodes).