Storage

Introduction TL;DR: Kubernetes Volumes provide a durable storage solution to solve the ephemeral nature of container filesystems, ensuring data persists even when a Pod restarts. The core of Kubernetes storage is an abstraction layer consisting of three key objects: PersistentVolume (PV), PersistentVolumeClaim (PVC), and StorageClass. An administrator defines available storage as a PV, a user requests storage with a PVC, and a StorageClass enables the dynamic, automatic provisioning of PVs to satisfy PVCs, streamlining storage management in cloud environments. By default, a container’s filesystem is ephemeral. Any data created inside a container is lost when the container is terminated and restarted. To run stateful applications like databases, it’s essential to have a mechanism for persistent storage. Kubernetes Volumes address this by decoupling the storage lifecycle from the Pod lifecycle. A Volume is essentially a directory, accessible to the containers in a Pod, whose data can be preserved across container restarts. ...

In this guide, we’ll explore Longhorn, a lightweight, reliable, and open-source distributed block storage system for Kubernetes. You’ll learn what Longhorn is, how it works, how to install it using Helm, and how to monitor it with Grafana and Prometheus. Table of Contents 1. What is Longhorn? Longhorn turns the local disks of your Kubernetes cluster nodes into persistent volumes — making stateful apps like databases possible in Kubernetes. Think of it this way: ...