as far as NFS you can deploy that on VMware and utilize the de-dupe feature. just add a switch if you are concerned with throughput.
VNXe NFS dedupe is file based. Your VMDK's will have to have MATCHING checksum's unless they've done something crazy.
If you use it as a NAS sure you'll get some dedupe, but if you have massive amounts of duplicate file's you REALLY need to getyourdocumentmanagementunder control. There is a performance overhead associated with this technology.
Regarding backup: the vnxe has an NDMP feature to utilize with tape or disk.
Or you can just have backup software that dirrectly mounts the iSCSI LUN's (Like Veeam) and does the same thing without expensive NDMP licensing.
If you want to stick all in the family, the VNXe3100 with a DataDomain for...