We have a business need where we need to transfer a 250GB file in less than an hour from a portable USB drive to a NetApp FAS6290. I would like to see if it is technically possible to plug in the USB drive directly to the filer head so that I can do some NetApp ONTAP magic (sm2tape, ndmpcopy, etc) to copy the data to and from the USB drive without having to involve the network in any way.
It is possible to do SMTape to file on NetApp; then you can copy this file to external client and transfer to remote NetApp. You still need enough space on source and destination to do it. Also this is diag level option so usual warning applies.
I am not aware of any possibility to connect USB storage device directly to NetApp, and even if this were possible, I would be very surprised if it could be accessed on WAFL layer.