I must admit the storage management business has been somewhat of a black hole to me before. Not the Economist tries to shed some light on it:

"DAS still accounts for about 70% of all data stored today. But it is already becoming pass�. That is because, in the late 1990s, EMC came up with a bright idea. Companies could use their storage capacity more efficiently by creating internal networks that connect a bunch of computers on one side with a cluster of storage arrays on the other. Stephen Chin, an analyst at UBS, an investment bank, reckons that such storage-area networks (SANs) can boost the utilisation rate of hardware to as much as 80%, from about 20% in the one-array-per-computer world of DAS."

"EMC's boffins have now come up with a new idea: storage networks are great, but they still fall short in this brave new world of red tape by treating all information as the same, when blatantly it is not. There are this quarter's profit numbers, and then there are the payroll figures for that receptionist who was laid off ten years ago. The former is clearly more valuable, and deserves costlier technology, than the latter. Technology buyers, with today's tight budgets, want systems that do not overcharge for storing all the junk."