To prevent damage to the Kubernetes cluster, we recommend deleting all Kubernetes workloads using Longhorn volumes (PersistentVolume, PersistentVolumeClaim, StorageClass, Deployment, StatefulSet, DaemonSet, etc).

Uninstalling Longhorn using kubectl

1. Create the uninstallation job to clean up CRDs from the system and wait for success:

kubectl create -f https://raw.githubusercontent.com/longhorn/longhorn/v0.8.0/uninstall/uninstall.yaml
kubectl get job/longhorn-uninstall -w

Example output:

$ kubectl create -f https://raw.githubusercontent.com/longhorn/longhorn/v0.8.0/uninstall/uninstall.yaml
serviceaccount/longhorn-uninstall-service-account created
clusterrole.rbac.authorization.k8s.io/longhorn-uninstall-role created
clusterrolebinding.rbac.authorization.k8s.io/longhorn-uninstall-bind created
job.batch/longhorn-uninstall created

$ kubectl get job/longhorn-uninstall -w
NAME                 COMPLETIONS   DURATION   AGE
longhorn-uninstall   0/1           3s         3s
longhorn-uninstall   1/1           20s        20s
^C

2. Remove remaining components:

kubectl delete -f https://raw.githubusercontent.com/longhorn/longhorn/v0.8.0/deploy/longhorn.yaml
kubectl delete -f https://raw.githubusercontent.com/longhorn/longhorn/v0.8.0/uninstall/uninstall.yaml

Tip: If you try kubectl delete -f https://raw.githubusercontent.com/longhorn/longhorn/v0.8.0/deploy/longhorn.yaml first and get stuck there, pressing Ctrl C then running kubectl create -f https://raw.githubusercontent.com/longhorn/longhorn/v0.8.0/uninstall/uninstall.yaml can also help you remove Longhorn. Finally, don’t forget to cleanup remaining components.

Uninstalling Longhorn from the Rancher UI

From Rancher UI, navigate to Catalog Apps tab and delete Longhorn app.

Uninstalling Longhorn using Helm

helm delete longhorn --purge

Troubleshooting

I deleted the Longhorn App from Rancher UI instead of following the uninstallation procedure

Redeploy the (same version) Longhorn App. Follow the uninstallation procedure above.

Problems with CRDs

If your CRD instances or the CRDs themselves can’t be deleted for whatever reason, run the commands below to clean up. Caution: this will wipe all Longhorn state!

# Delete CRD finalizers, instances and definitions
for crd in $(kubectl get crd -o jsonpath={.items[*].metadata.name} | tr ' ' '\n' | grep longhorn.rancher.io); do
  kubectl -n ${NAMESPACE} get $crd -o yaml | sed "s/\- longhorn.rancher.io//g" | kubectl apply -f -
  kubectl -n ${NAMESPACE} delete $crd --all
  kubectl delete crd/$crd
done

Volume can be attached/detached from UI, but Kubernetes Pod/StatefulSet etc cannot use it

Check if volume plugin directory has been set correctly. This is automatically detected unless user explicitly set it. Note: The FlexVolume plugin is deprecated as of Longhorn v0.8.0 and should no longer be used.

By default, Kubernetes uses /usr/libexec/kubernetes/kubelet-plugins/volume/exec/, as stated in the official document.

Some vendors choose to change the directory for various reasons. For example, GKE uses /home/kubernetes/flexvolume instead.

User can find the correct directory by running ps aux|grep kubelet on the host and check the --volume-plugin-dir parameter. If there is none, the default /usr/libexec/kubernetes/kubelet-plugins/volume/exec/ will be used.

Please see link for more information.