Longhorn Tutorial: Kubernetes Storage Made Simple (Install & Monitor Guide)

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.

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:

You run a blog inside a Kubernetes pod. What happens to your blog content when the pod restarts?
Without persistent storage, the data is gone.
Longhorn ensures that data is stored on disk, replicated, and recoverable — even if nodes go down.

Key Features

• Easy installation with Helm
• Web UI for managing volumes and nodes
• Built-in snapshot and backup
• Supports high availability with volume replication
• Integrates with Prometheus for monitoring

2. How to Install Longhorn (with Helm)

We’ll use Helm to install Longhorn on your Kubernetes cluster.

Step 1: Install Helm (if not installed)

curl https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash

Step 2: Create a Namespace

kubectl create namespace longhorn-system

Step 3: Add the Longhorn Helm Repository

helm repo add longhorn https://charts.longhorn.io
helm repo update

Step 4: Install Longhorn

helm install longhorn longhorn/longhorn --namespace longhorn-system

This installs the Longhorn controller, manager, UI, and CRDs.

3. Access the Longhorn Dashboard

Longhorn comes with a built-in web UI to view and manage volumes.

Port Forward to Access Locally

kubectl port-forward -n longhorn-system service/longhorn-frontend 8080:80

Then visit:

http://localhost:8080

Here, you can view your volumes, replicas, disk usage, and even take snapshots and backups.

4. Monitor Longhorn with Prometheus & Grafana

Longhorn exports metrics to Prometheus and has an official Grafana dashboard.

Enable Monitoring Support via Helm

You can enable monitoring by setting these values during installation:

serviceMonitor:
  enabled: true
defaultSettings:
  telemetryOpt: true

If already installed, go to the Longhorn UI > Settings and enable telemetry.

Import Grafana Dashboard

In Grafana, use the official dashboard ID:

• Grafana Dashboard ID: 13032

This dashboard includes disk usage, replica health, volume throughput, and more.

5. Summary

Longhorn makes persistent storage on Kubernetes clusters easy and reliable. With a simple Helm install, built-in dashboard, and strong monitoring support, it’s ideal for running stateful workloads in production.

Highlights:

• Lightweight distributed block storage
• Easy to install and scale
• Supports snapshots and backups
• Works with Prometheus and Grafana

Conclusion

Whether you’re running databases, message queues, or other stateful apps in Kubernetes, Longhorn provides a robust and user-friendly storage solution.

In future posts, we’ll dive deeper into backup to S3, disaster recovery, and volume snapshot automation with Longhorn.