Persistent Volumes

Persistent Volumes (PVs) in Kubernetes provide a mechanism for managing storage resources independently of individual Pods. Unlike ephemeral storage, which is tied to the lifecycle of a Pod, PVs ensure data persistence across Pod restarts and rescheduling, enabling stateful applications to function reliably in a Kubernetes cluster.

In Kubernetes, storage resources are abstracted through the Persistent Volume framework, which decouples storage provisioning from application deployment. A Persistent Volume (PV) represents a piece of storage that has been provisioned in the cluster, while a Persistent Volume Claim (PVC) is a request for storage made by an application.

Key characteristics of Persistent Volumes include:

• Decoupled Storage Management: PVs exist independently of Pods, allowing storage to persist even when Pods are deleted or rescheduled.
• Dynamic and Static Provisioning: Storage can be provisioned manually by administrators (static provisioning) or automatically by storage classes (dynamic provisioning).
• Access Modes: PVs support multiple access modes, such as ReadWriteOnce (RWO), ReadOnlyMany (ROX), and ReadWriteMany (RWX), defining how storage can be accessed by Pods.
• Reclaim Policies: When a PV is no longer needed, it can be retained, recycled, or deleted based on its configured reclaim policy.
• Storage Classes: Kubernetes allows administrators to define different types of storage using StorageClasses, enabling automated provisioning of PVs based on workload requirements.