Customer's vSphere team reporting a high number of alerts from OpenShift environment.  It looks as if external-attacher sidecar attempts to retry the detach despite already succeeding:-
- Task Name: Detach a virtual disk
- Status: The object or item referred to could not be found

This does not appear to impact the running openshift cluster.

Originating case: 03872877.

    4.13.34+

    Reproducible, but some clusters effected more than others.

    1. Perform operation triggering unmount
    2. Observe vSphere errors (and CSI driver logs)
    

From CSI Driver:
---
csi_handler.go:289] Failed to save detach error to "csi-xxxx": volumeattachments.storage.k8s.io "csi-xxxx" not found

csi_handler.go:234] Error processing "csi-xxxx": failed to detach: could not mark as detached: volumeattachments.storage.k8s.io "csi-xxxx" not found

csi_handler.go:706] Removed finalizer from PV "pvc-xxxx"

csi_handler.go:701] Failed to remove finalizer from PV "pvc-xxxx": PersistentVolume "pvc-xxxx" is invalid: metadata.finalizers: Forbidden: no new finalizers can be added if the object is being deleted, found new finalizers []string{"kubernetes.io/pv-protection"}
---

From vSphere:
---
Task Name: Detach a virtual disk
Status: The object or item referred to could not be found
---

Error free operation, no vSphere alerts.