dNFS as in "direct NFS"?

If so, I don't see why not. There is nothing that I can see that has to be done on the server side to support this (Isilon cluster)

Here is an ancient whitepaper describing dNFS

http://www.oracle.com/technetwork/articles/directnfsclient-11gr1-twp-129785.pdf

i am curios too for my rman backups to isilon rather than expensive Data domain, but i guess isilon doesn't have de-dup / compression features yet

I don't see why not however, dedupe won't be available until later this year as far as I know. That and dedupe will be a licensed feature... Ie: you will have to pay per node in your cluster.

Honestly if you are looking for "cheap" backup storage then Isilon/DataDomain are likely are not what you are looking for

Sent from my HTC

define "cheap" ?, i have many Oracle boxes doing RMAN backups to DD and get insanely good dedupe/compression ratio (126x) so price per gigabyte is very competitive to compatible boxes from competition.

(126x)???  looks like its working best for you. for us its 9x ( fyi..no compression/zip files on server  )  i agree DD is great product but i still believe its sort of expensive  than dedup prod like Quantum

Well *personally* I cringe when the pricing for these dedupe HW products (DataDomain, ExaGrid for example) are just as pricey as primary storage.

Plenty of SW only products out there that will do just as well with Inline dedupe/compression. Heck (wow I can say he-double-hockey-sticks!), there are other file systems out there that will do quite decent dedupe/compress post.

price per /gb might be even more expensive than primary storage but when you start looking at your duplication rate it becomes a very compelling story.