Important: Please install the Longhorn chart in the longhorn-system namespace only.

Warning: Longhorn doesn't support downgrading from a higher version to a lower version.

Longhorn is 100% open source software. Project source code is spread across a number of repos:

1. Longhorn Engine -- Core controller/replica logic https://github.com/longhorn/longhorn-engine
2. Longhorn Instance Manager -- Controller/replica instance lifecycle management https://github.com/longhorn/longhorn-instance-manager
3. Longhorn Share Manager -- NFS provisioner that exposes Longhorn volumes as ReadWriteMany volumes. https://github.com/longhorn/longhorn-share-manager
4. Longhorn Manager -- Longhorn orchestration, includes CSI driver for Kubernetes https://github.com/longhorn/longhorn-manager
5. Longhorn UI -- Dashboard https://github.com/longhorn/longhorn-ui

1. Docker v1.13+
2. Kubernetes v1.16+
3. Make sure curl, findmnt, grep, awk and blkid has been installed in all nodes of the Kubernetes cluster.
4. Make sure open-iscsi has been installed in all nodes of the Kubernetes cluster. For GKE, recommended Ubuntu as guest OS image since it contains open-iscsi already.

1. Add Longhorn chart repository.

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

2. Update local Longhorn chart information from chart repository.

helm repo update

3. Install Longhorn chart.

• With Helm 2, the following command will create the longhorn-system namespace and install the Longhorn chart together.

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

• With Helm 3, the following commands will create the longhorn-system namespace first, then install the Longhorn chart.

kubectl create namespace longhorn-system
helm install longhorn longhorn/longhorn --namespace longhorn-system

With Helm 2 to uninstall Longhorn.

helm delete longhorn --purge

With Helm 3 to uninstall Longhorn.

helm uninstall longhorn -n longhorn-system
kubectl delete namespace longhorn-system

Please see link for more information.