Hi,  1) No. Only gateway systems support adittional backends. 2) See #1. 3) Yes. A Celerra gateway can have up to 4 backends in any mix of CLARiiONs and Symmetrix/DMX.   Gustavo Barreto. 
Folks, I would appreciate if you could answer the following questions for me:  1) We have a NS480 Celerra connected to clariion backend and serves as unified for both SAN and NAS. We are running out of space on this backend clarrion but have plenty of space in another clariion CX3-80 which currently serves only SAN. Is it possible to add this Clarrion CX3-80 to the backend of this NS480 Celerra?.  2) If answer to above question is yes, then what steps do i need to take to add another array to Celerra backend.  3) If answer to above question is yes, then can we add any EMC array as backend to Celerra gateway?. Is there any limitation on number of backend arrays, etc?  Thank you very much.
Celerra NS480 gateway backend storage