The Pros and Cons of Dense Storage


One thing that never stops in the storage industry is the drive for greater density. Higher concentration of resources on a smaller physical footprint will always be in demand even if IT infrastructure is pushed past the cloud onto -- what's next? The moon? (Moon Computing, you heard it here first.)

But at some point, increased storage density will start to have negative effects on data center economy and efficiency, mainly in the power draw. So it's appropriate to do a little due diligence on both the positive and negative effects that your new box will have on your overall operation.

On the plus side, it's hard to counter the capacity/per-square-foot argument. The newest design from Celerra, the CX4, can pack an equal number of 2TB SATA drives, plus SSDs, in half the frame that earlier Celerra's needed to hold 1 TB drives. And the company says that byte-for-byte, the new denser design featuring power spin-down and EMC's FAST automated tiering system, plus the fact that the new drives cut the spin velocity from 7200 rpm to 5200, produces a 60 percent reduction in power usage.

Similar arguments can be heard from other storage vendors. Super Micro features a double-sided chassis on its SC847 that can hold up to 36 hot-swappable 2.5-inch drives (24 in the front and 12 in the rear) in a 4U space. The system features redundant power supplies and the Power Management Bus (PMBus) protocol to keep power use to a minimum.

Increased density is reaching right down into memory as well. SMART Modular Technologies has a new set of DDR3 modules that can deliver up to 4 GB on the same 18.8mm form factor (or 8 GB on 30mm) as its DDR2 devices. The company is eyeing everything from industrial and telecom applications to networking and storage, touting advantages like unbuffered and registered error-correction code (ECC) and very low profile (VLP) mini-DIMM design.

Clearly, then, there is not much wrong technology-wise with the new hardware. But some are questioning whether a good number of enterprises wouldn't be better off investing in new software to make existing system more efficient, rather than laying out for entirely new hardware. Staples Technology Solutions' Steven Suesens argues that effective use of virtualization and load balancing can free up surprisingly large amounts of existing storage, while power management and improved cooling practices can also drawn down the energy bill.

There is, of course, no reason IT managers can't pursue both a hardware and software course to lower power consumption. The danger is to provision new high-density storage and then simply add more hardware to meet steadily increasing capacity requirements. That merely increases the power draw per square foot for data that might be redundant or superfluous.

The old mantra in data center design used to be Field of Dreams' "Built it and they will come." Nowadays we are finding out that users and their the data just keep coming and coming no matter what you do. And if you don't manage data and resources properly, you'll be force to build again before you're ready.