Persistent Volume (PV) and Persistent Volume Claim (PVC) are fundamental concepts in Kubernetes storage management.

PV serves as a representation of a storage volume, defining the available storage within a cluster.

PVC, on the other hand, is a binding between a Pod and a PV, signifying the pod’s request for storage resources.

By decoupling the storage requirements of pods from the actual storage implementation, PV and PVC facilitate effective storage management in Kubernetes.

The concept of Storage Class enables dynamic provisioning of PVs, allowing for the definition of different storage classes with varying performance characteristics.

PVCs can request storage from a specific Storage Class, and Kubernetes automatically provisions a suitable PV.

Understanding the distinction between PV and PVC is crucial for ensuring that pods have the necessary storage resources while abstracting the complexities of the underlying storage infrastructure.

This article aims to clarify the difference between PV and PVC in a simplified manner.

Persistent Volume (PV)

A Persistent Volume (PV) is a low-level representation of a storage volume that defines the storage resources available for allocation to Persistent Volume Claims (PVCs).

It acts as a provisioned storage resource in a cluster, independent of any specific Pod.

PVs can be created statically or dynamically using Storage Classes.

They have a lifecycle independent of any individual Pod and can be dynamically provisioned or manually created by a cluster administrator.

PVs can be of different types, such as network-attached storage or host-local storage, depending on the underlying infrastructure.

They provide a way to share storage resources across multiple Pods and can be accessed by multiple Pods simultaneously.

PVs are bound to PVCs, which act as a request for storage and define the desired characteristics of the storage volume.

Persistent Volume Claim (PVC)

Persistent Volume Claim (PVC) establishes a binding relationship between a Pod and a specific storage resource, allocating the necessary resources for the Pod’s storage requirements.

PVCs are used by Pods to request storage resources from the underlying storage system. When a Pod needs storage, it creates a PVC with specific requirements such as the desired storage capacity and access mode.

The Kubernetes control plane then tries to find a suitable Persistent Volume (PV) that meets these requirements. Once a matching PV is found, the PVC binds to it, and the Pod can use the storage provided by the PV.

PVCs abstract the underlying storage details, allowing Pods to be decoupled from the specific storage implementation. This enables portability and flexibility in managing storage resources for Pods in a Kubernetes cluster.

Storage Class

The Storage Class feature in Kubernetes enables the dynamic provisioning of Persistent Volumes, allowing for the on-demand creation of storage resources based on predefined policies and parameters.

It provides a way to define different classes of storage with varying properties, such as performance, availability, and cost.

When a Persistent Volume Claim (PVC) is created, it can request a specific class of storage, and the Storage Class will dynamically provision a matching Persistent Volume (PV) based on the defined parameters.

This allows for more efficient utilization of storage resources and simplifies the management of storage in Kubernetes clusters.

The Storage Class can also be used to automatically reclaim or delete unused Persistent Volumes when they are no longer needed, ensuring efficient resource utilization.