The terms "scalable" and "network-attached storage" rarely appear together in the same sentence, simply because no one expects NAS to scale out. Traditionally, NAS has been just one flavor in the spectrum of storage technologies--a flavor that is only meant to meet the needs of storing files on a network for access by a few or for backup purposes.
When it comes to scalability, NAS usually defers to storage area network (SAN) technologies, which by design support scale-out and storage growth needs. That is not to say that NAS has no business being in the realm of scalable storage; it is just that was not the intention of NAS to begin with.
Enterprises are adopting scale-out architectures, says Kurt Marko, a regular contributor to Network Computing and InformationWeek, as well as the author of the new Research: State of Storage 2012 InformationWeek report. It's not a new concept, but a new generation of products supporting iSCSI, block storage on distributed file systems and cloud stacks that work in what is essentially a distributed file system, coming onto the market to join the NAS-based systems historically associated with scale-out architecture.
"I think you're going to see those systems displace some of the big monolithic arrays for many applications, particularly unstructured data and maybe some big data apps like Hadoop and applications that are designed to take advantage or designed to use distributed data. Those can really take advantage of this build-as-you-grow architecture," says Marko.
EMC is one company that is looking to change the ideology that NAS doesn't scale and SANs rule supreme in network infrastructures where storage flexibility is of the utmost importance. So, how exactly is EMC going about that paradigm shift? The simple answer comes in the form of the Seattle-based Isilon acquisition, the purchase of a storage company that has specialized in easy-to-configure NAS systems for enterprise-level storage needs.
However, it takes more than purchasing a competing technology to achieve scale-ability nirvana for NAS in the enterprise. It takes identifying core technological capabilities, practices and a thorough understanding of how data storage interacts with the network.
Nevertheless, one has to wonder why NAS should move into the realm of scalability. After all, SAN technologies seem to have an effective handle on the demands of network storage. Two factors have helped to transform NAS into a logical path into scale-out storage. The first is cost: NAS proves to be much less expensive to purchase and deploy than a traditional SAN. The second factor is the big data movement, where businesses are looking to store large amounts of unstructured data for business analytics purposes. (The key here being unstructured.)