Hmmmm, I have an F540 filer. I'm sure it's a 540. Positive. Says 540 on it somewhere. I'm sure.

Its all a marketing thing, when the 630 came in the 540 sounded too far up the product line. The differences as far as I know are lack of shiny panel and a reduction in the capacity they'd let you attach to a 520.

No such thing as a 540 on www.netapp.com. There's a 520, which looks pretty darn similar. Can I just s/540/520/g, and be a happy camper?

Pretty much