Only the MDCs are required to see the Metadata LUN. The rest of the clients receive the extents from the MDCs to write to the “data” LUNs. Yes the clients need to see the Data LUNs, but clients do not need to see Metadata LUNs. Before you can upgrade a client to an MDC though, verify that you can see the Metadata LUNs if you are zoning this way. It’s the most secure way but requires a little extra zoning.