One thing that continues to puzzle is "networked storage." What is it? Has it arrived or is it another "vision" -- like Information Lifecycle Management or Utility Storage? It seems to me that all storage is networked, by virtue of the fact that we access it across a LAN from our workstations, web browsers, or laptops. Yet, what if any of the current storage technologies packaged as "networked storage" actually are?

We know that direct attached storage (DAS) isn't networked storage. At least, that is what the vendors and SNIA have been telling us. Directed attached storage (DAS) is storage directly tethered to a server, a whipping boy of the networked storage crowd.

But what about Network-Attached Storage (NAS)? Now that sounds like it could be networked storage. Heck, it even says so in the name. But is NAS networked storage? A NAS box is just a thin operating system "head" (read general purpose server tuned to do network and storage I/O) directly attached to a bunch of trays of disk drives (a direct attached array). How is this any more networked than a DAS solution, which may also be accessed via network file system protocols like NFS or CIFS/SMB?

Then you have Storage Area Networks (SANs): the name is also encouragingly "networked storage" sounding. But, Fibre Channel, the protocol used to connect up storage and servers is not a network protocol: it is, as its name suggests, a channel protocol.

Fibre Channel SANs use a switch to make and break point-to-point connections between servers and storage at high speed. It is rather like using a roundhouse in a toy train track to switch the locomotive to alternate sets of tracks. Is that a network? Not according to network guys. That is direct attached storage with a switch in the middle.

So, one could say that no storage offered today is networked storage. Or maybe all of it is. It makes you crazy.