Over its 20 year history, innovation in the field of enterprise storage has seemed to focus on two often conflicting goals: ever-expanding capacity and the need to access all of that storage. Nearly every development seems to come down to one of these two areas. In this time of cloud storage and big data, it is illuminating to consider the challenges in light of capacity and accessibility.
Starting at the very beginning, it's amusing to note that the original RAID paper was focused on a pending crisis of I/O performance, not a challenge to build larger and larger storage systems. The fact that RAID technology became the foundation for the entire enterprise storage industry should come as no surprise, but this history is surprisingly repetitive. Every few years, a new advancement in capacity would drive a demand for better performance or easier accessibility. But once this was reached, industry attention would turn once again toward expanding capacity to fill this I/O channel.
File servers provided easier access to shared storage, and quickly grew in capacity. This led to the need for DRAM buffers so advanced caching storage systems like the EMC Symmetrix and Data General CLARiiON were born. This new threshold of performance sparked a growth in capacity once again, with familiar refrigerator-sized storage systems appearing throughout the data centers of the world. Sharing all this capacity drove a demand for Fibre Channel storage area networks (SANs), which again sparked a growth in storage capacity. ISCSI was the next major innovation in storage accessibility, bringing enterprise storage features out of the stratosphere and sparking the growth of companies like EqualLogic, LeftHand and NetApp.
If we take this pattern of capacity growth followed by accessibility into today, where does it put us? The answer was suggested by Andres Rodriguez, founder and CEO of Nasuni and one of my clients. We were discussing the fact that cloud storage service providers seem to have finally figured out how to build an infinitely scalable system. I know this for a fact because I spent a year working at enterprise cloud storage provider Nirvanix before striking out on my own. Cloud storage platforms like the one I saw at Nirvanix really can scale without limit, spanning discs, servers, data centers and continents.
Clearly, cloud storage can scale. But the gating factor in its use is an issue of accessibility. Put simply, cloud storage systems have not traditionally been accessible to the majority of data center or corporate applications. But this is changing, as companies like Nasuni, CommVault, Symantec and many others create cloud gateways that let conventional applications use this new class of storage. With the benefit of historical context, we see that the rise of cloud storage is not in fact an unprecedented event. It is merely the latest move in a series of bounces between capacity and accessibility.