The vSphere CSI Driver RWO block volume could not be mounted multiple times on a single node with error: block volume already mounted in more than one place

4.12+    

Always    

    1. Create pvc with Block volumeMode and RWO accessMode
    2. Make only one worker schedulable to ensure pods could land on the same node
    3. Create first pod to consume the pvc, pod is running
    4. Create second pod to consume the same pvc, pod stays ContainerCreating with block volume already mounted in more than one place

$ oc get pod,pvc
NAME                              READY   STATUS              RESTARTS   AGE
pod/mydep-block-fcb44c8c6-zch5b   1/1     Running             0          163m
pod/mypod-block                   0/1     ContainerCreating   0          162mNAME                                STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   VOLUMEATTRIBUTESCLASS   AGE
persistentvolumeclaim/mypvc-block   Bound    pvc-35bc3be5-ff83-4acd-b138-7d5fc4a6ce30   1Gi        RWO            thin-csi       <unset>                 163m   

$ oc describe pod mypod-block
  Warning  FailedMapVolume  17s (x87 over 161m)  kubelet            MapVolume.MapPodDevice failed for volume "pvc-35bc3be5-ff83-4acd-b138-7d5fc4a6ce30" : rpc error: code = AlreadyExists desc = block volume already mounted in more than one place  

The vSphere CSI Driver RWO block volume could not be mounted multiple times on a single node   

The vSphere CSI Driver RWO block volume should be able to be mounted multiple times on a single node

Verified in 4.12 cluster, in-tree(without CSIMigration) actually does support it and the CSI Driver doesn't support it from that monent.