Virtual machine > Configuration > Add or remove device
If the IBM Storage Support for Microsoft VSS and VDS communicate with the vCenter server, you must
assign the Read-Only role to the data center to which the VMware ESX(i) server belongs.
You can view the user privileges by accessing the vSphere client
and selecting the Permissions tab. Role settings in the vCenter server
list the roles and permissions for the vCenter server. Figure 1. vSphere client - user privileges