The NAS code in VNX (v.7.x) had to be modified in order to support the FASTVP pool on the back end. In DART 6 and previous, the NAS expects specific WWN, RAID info, etc from the LUNs on the backend in order to know how to build the storage pools for the NAS file systems. DART 6.x would not recognize the LUNs from a FASTVP pool correctly and the behavior would be inconsistent.  Richard J Anderson
I have 2 x NS4-120's. CX4-120 at the backend and data movers up front.  Running FLARE 30 and DART 6.0 I used some disk for NAS and Data Mover access, and some for block IO out to hosts. Unified storage.  I know that i can license FAST VP and get some auto-tiering going on my array, but i want to use FAST on BOTH file and block data. I read somewhere that with the CX4 backend i can only do FAST VP for block data.  Is this correct? Is FAST VP for File only supported on VNX??
FAST VP for Data Movers on CX4