I think I get what you're trying to accomplish. I'm going to be a bit repetitive first for future readers though for sake of clarity.
As previously posted in this thread, NetApp doesn't set or recognize volumes as storage type SAN or storage type NAS. The concepts as you are describing your setup do not exist.
NetApp uses a volume as the logical allocation of data. Within the NetApp, all data is stored as individual files. A file on a volume is accessed by one of four main protocols (levaing out 7-mode http and ftp for now). Two protocols - CIFS and NFS - access each file as a stream of bytes. While these two protocols are typically referred to as "NAS", there is nothing about the volume or the files that mark them as "NAS".
Similarly, the other two protocols - FC and iSCSI - access each file as directly accessible blocks. These two block style protocols are typically referred to as "SAN" but again, there is nothing about the volume or the files that mark them as "SAN".
In the NetApp unified model, any file can be accessed by any protocol in general (granted it takes some doing). For instance, if you create a LUN on a volume and setup FC access to the LUN to some host. You can also define a CIFS style share on the same volume, access the volume from another place with a CIFS session, and you'll see the LUN sitting out there as a generic file. But, if you open the LUN file, you don't see the same contents of the LUN as the FC host sees. Instead you see the LUN file as a raw stream of bytes, like a disk image file. That's literally what it is after all. The contents of a LUN file don't make sense except when connected to a controlling host that can interpret the blocks through the lens of a logical file system, partitions, and all that disk stuff.
So you see, a volume can contain any kind of file at any time - there isn't a NAS volume or a SAN volume. There are just files and access protocols. The access protocols do tend to dictate the interpretation of the individual files. The access protocol used does not indicate the "type" of volume.
Now to your exact scenario. Given you have a ton of files on a volume. You want to allow a host to see those as a LUN. The volume is not the LUN, so you have to somehow copy the files into a disk image file as a LUN. NetApp provides no means to do that - how could it. Which file system do you want inside that LUN? What directory structure inside the LUN? What partitioning scheme inside the LUN? Questions like that abound. NetApp has no means to support the diverse possibilities that exist in the general world. Remember that even though Data OnTAP holds the data for a LUN, Data OnTAP has no idea what the file structure or style or anything is inside the LUN. That detail is opaque and doesn't matter to storage because storage need only deliver blocks on demand as a host OS requests them per it's own interpretation of what the block contents mean.
You will have to manually create a LUN and transfer the individual files into the LUN as if you were transferring data between two servers. There is no automatic way to do this activity in anyone's storage that I can think of off hand.
I hope this helps you.
Bob Greenwald
Lead Storage Engineer
Huron Legal | Huron Consulting Group
NCDA, NCIE SAN Clustered, Data Protection
Kudos and accepted solutions are always appreciated.
