Almost every storage vendor claims that its technology cuts power and cooling needs. Most pitches have at least a grain of truth, since anything that reduces data volume also reduces energy costs. Here are eight ways to start saving.
1 Information life-cycle management (ILM) is as much a management philosophy as a technology and involves moving data to less-expensive systems or eliminating it as its value falls. Many vendors provide software and services to help customers implement ILM. For example, EMC recently introduced a program called Energy Efficiency Services through which it helps customers estimate energy consumption of specific EMC product configurations under various workloads.
2 Another common data centre strategy — virtualisation — makes more efficient use of both servers and storage by combining physical devices into logical “pools” that can be more completely utilised than separate, stand-alone devices. This can cut power demands by reducing the physical servers and storage an organisation requires. But it can also increase power demands by using very dense racks of servers and storage that max out the power capacity of data centres long before they are physically full.
3 De-duplication and compression can yield a 20-to-1 reduction in storage needs by storing only the differences between old and new copies, or by reading data as it is written to the backup device and storing only the unique data. Among the vendors offering such products are Data Domain, ExaGrid Systems, Asigra and Avamar Technologies, now owned by EMC.
4 By allocating as much “logical” capacity on drives as applications are expected to require but allocating physical capacity as the applications actually need it, storage servers from vendors such as 3PARdata postpone the need for additional drives. This approach, also known as thin provisioning, gives storage managers more time to juggle capacity and buy drives.
5 More possible power savings come from MAID (massive array of idle disks) storage from vendors such as Copan Systems. This technology spins up a drive only when data is required from it. But the extra time required to spin up the drive can make MAID unfeasible for applications such as transaction processing, which require high performance.
6 Still other vendors tackle overall storage management costs, and therefore power issues, with combinations of specially designed hardware and software. BlueArc, for example, claims its Titan 2200 file server, which can serve as a front end for multiple storage-area network or network-attached storage systems, generates one-third the heat and provides twice the performance of competing high-end NAS hardware. Agami Systems uses 64-bit Opteron chips to create high-end NAS servers that consume half the power and as little as one-eighth the space of other NAS hardware, says Paul Speciale, vice president of product management.
7 Some vendors have built temperature sensors into storage arrays and other hardware to direct cooling to where it’s needed most. For example, Hewlett-Packard claims that its Dynamic Smart Cooling System can save 25 percent to 40 percent of a data centre’s energy use.
8 Finally, and furthest in the future, is the prospect of replacing power supplies that convert AC power into DC power for individual servers and storage devices with centralised DC-based power distribution systems. Backers say such centralised systems are more efficient than many of the individual power supplies that ship with typical servers and storage, and some small server vendors have shifted to DC power.
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