updated troubleshooting doc for PowerFlex (#551)

content/docs/csidriver/troubleshooting/powerflex.md

@@ -23,6 +23,7 @@ description: Troubleshooting PowerFlex Driver
 | When a node goes down, the block volumes attached to the node cannot be attached to another node                                           | This is a known issue and has been reported at https://github.com/kubernetes-csi/external-attacher/issues/215. Workaround: <br /> 1. Force delete the pod running on the node that went down <br /> 2. Delete the volumeattachment to the node that went down. <br /> Now the volume can be attached to the new node.                   |
 | CSI-PowerFlex volumes cannot mount; are being recognized as multipath devices | CSI-PowerFlex does not support multipath; to fix: <br/> 1. Remove any multipath mapping involving a powerflex volume with `multipath -f <powerflex volume>` <br/> 2. Blacklist CSI-PowerFlex volumes in multipath config file |
  | When attempting a driver upgrade, you see: ```spec.fsGroupPolicy: Invalid value: "xxx": field is immutable``` |  You cannot upgrade between drivers with different fsGroupPolicies. See [upgrade documentation](../../upgradation/drivers/powerflex) for more details | 
+ | When accessing ROX mode PVC in OpenShift where the worker nodes are non-root user, you see: ```Permission denied``` while accesing the PVC mount location from the pod. | Set the ```securityContext``` for ROX mode PVC pod as below, as it defines privileges for the pods or containers.<br/><br/>securityContext:<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;runAsUser: 0<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;runAsGroup: 0 |
 
 >*Note*: `vxflexos-controller-*` is the controller pod that acquires leader lease