ENERGY STAR for buildings, homes and products has been in place for quite some time now and we've become familiar with those yellow EnergyGuide labels when shopping for appliances. What about data center storage? We don't expect to see those yellow labels anytime soon on storage systems, however certified energy efficiency data is compiled here. Now buyers of storage systems have the same objective comparison data for their storage to help purchase cost saving, energy efficient products.
The storage specification may have been a long time coming, but Hitachi has been designing for the environment for years. In lieu of global standards, Hitachi created Eco-products in designing and developing products to minimize their environmental impact. Products are documented for their energy efficiency, material impact, packaging and chemical content. Hitachi describes their methodology as Factor X.
Our first ENERGY STAR certified product is the Hitachi Unified Storage VM. To be clear, this class is online storage (intended to service a mixture of random and sequential I/O requests with a short response time) in category 4. Online 4 products are network connected with an integrated controller providing data protection with no single point of failure supporting over 100 storage devices. The definition matters when comparing products for the desired purpose as all types are listed together. Some type of capacity optimizing practice (snapshots, thin provisioning, RAID, dedupe, compression) is required as well. That illustrates the complexity in storage compared to dishwashers. How much data protection do you need, what level of availability, performance, capacity etc? When comparing storage on the certified list its important to compare like for like for the desired purpose.
Buying data center storage isn't like buying a dishwasher and evaluating the ENERGY STAR data takes some effort. On the one hand, knowing your vendor design products with environmental impact in mind is useful to eliminate those solutions which will cost your company more in power and cooling. On the other hand, how do you know how much will be saved without that yellow EnergyGuide on each rack? HDS provides a calculator to help determine the efficiency of the specific configuration you are considering. Also look at the data provided in the ENERGY STAR listing. See if your vendor published IOPS/W for various workloads (read, write, random, sequential, idle) so you can effectively compare. Look at the 80Plus rating of the power supply for its efficiency (Gold is better than Silver). These details are in the advanced view of the certified listings where you can also export the data.
One watt-hour of energy savings at the storage level results in roughly 1.9 watt-hours of facility-level energy savings. These additional savings stem from reducing energy waste in the power infrastructure (e.g., power distribution unit, uninterruptible power supply) and reducing 24/7 energy needed to cool the waste heat produced by data storage. So take that next step in savings by requiring ENERGY STAR certification and transparency from your vendor on their environmental operating cost.