4. Make sure `curl`, `findmnt`, `grep`, `awk` and `blkid` has been installed in all nodes of the Kubernetes cluster.
5. 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. To prevent damage to the Kubernetes cluster, we recommend deleting all Kubernetes workloads using Longhorn volumes (PersistentVolume, PersistentVolumeClaim, StorageClass, Deployment, StatefulSet, DaemonSet, etc).
2. From Rancher UI, navigate to `Catalog Apps` tab and delete Longhorn app.
## 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.
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!