An arbitrary index number to identify a Real
Device(s) mapped to a Virtual Device.
This instance value uniquely identifies a
Real Device mapping entry for Virtual Device
within the context of a particular VSAN and
in the agent where an instance of this MIB
instrumentation is running.
When an entry is successfully created in this table,
the agent uses this instance identifier value to
update the value of cFcSdvVdRealDevMapList of
cFcSdvVirtDeviceTable to indicate that this
Real Device(s) entry is mapped for virtualization in
a Virtual Device (represented by cFcSdvVdIndex).