Longhorn — Cloud Native Distributed Block Storage for Kubernetes

What it is

Longhorn is a lightweight, reliable distributed block storage system for Kubernetes. It provides persistent volumes with built-in replication, snapshots, scheduled backups to S3-compatible storage, and disaster recovery. Each volume is an independent microservice managed by its own controller, which simplifies troubleshooting and prevents a single storage failure from affecting the entire cluster.

Longhorn targets Kubernetes administrators who need persistent storage without deploying heavyweight solutions like Ceph or GlusterFS. It is a CNCF incubating project maintained by SUSE/Rancher.

How it saves time or tokens

Setting up distributed storage on Kubernetes traditionally requires deep expertise in storage systems. Longhorn installs with a single kubectl apply and manages itself. Automatic replication ensures data survives node failures. Scheduled backups to S3 eliminate manual backup scripts. The built-in UI provides volume health, replica status, and snapshot management without additional tooling.

How to use

1. Install Longhorn on your Kubernetes cluster:

kubectl apply -f https://raw.githubusercontent.com/longhorn/longhorn/v1.6.0/deploy/longhorn.yaml

1. Wait for installation to complete:

kubectl -n longhorn-system get pods -w

1. Create a PersistentVolumeClaim using the Longhorn storage class:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: my-data
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: longhorn
  resources:
    requests:
      storage: 10Gi

Example

Configuring automated S3 backups:

# Create a backup target secret
apiVersion: v1
kind: Secret
metadata:
  name: s3-backup-target
  namespace: longhorn-system
stringData:
  AWS_ACCESS_KEY_ID: 'your-key'
  AWS_SECRET_ACCESS_KEY: 'your-secret'
  AWS_ENDPOINTS: 'https://s3.amazonaws.com'

Then set the backup target in Longhorn Settings to s3://my-backup-bucket@us-east-1/ and schedule recurring backups per volume.

Related on TokRepo

• AI Tools for DevOps — Kubernetes infrastructure and storage tools
• AI Tools for Self-Hosted — self-hosted infrastructure solutions

Common pitfalls

• Longhorn requires open-iscsi installed on all worker nodes; missing this dependency causes volume mount failures
• Three replicas (the default) require at least three nodes with available disk space; adjust the replica count for smaller clusters
• Snapshots consume disk space proportional to data changes; configure snapshot cleanup policies to prevent disk exhaustion