How to increase your storage energy efficiency
By Greg Schulz
Power and cooling issues have become (pun intended) a hot topic for IT-related equipment, especially video monitors, servers, networks and storage. The reasons for having an interest in power and cooling can be tied to green initiatives, budget concerns (rising energy prices) or simply to support growth for your applications and data requirements with an existing power and cooling capability.
Electrical power, along with heating, ventilation and air-conditioning (HVAC), have traditionally been an afterthought in the data center. Given the rise in energy prices, green and environmental awareness campaigns, and continued expansion of IT equipment to support more applications with larger data requirements, HVAC, power and floor space have taken on a new importance in many IT organizations.
Approaches to improve storage energy efficiency include:
Another way to reduce power consumption is to address your data footprint. One approach is to refresh your technology with either a complete storage system replacement or by replacing the disk drives. In either case, you'll need to account for data movement and migration. For example, you could replace older disk drives of the same or larger capacity with newer generation drives that may have better performance and lower power consumption.
For example, an early generation 73 GB (72 GB if you prefer) 15,000 rpm (15K) 2 Gbit Fibre Channel disk drive consumed about 18.74W (164.16kW annually) of power versus a current generation 15.5K (slightly faster) 4 Gbit Fibre Channel disk drive that consumes 15.24W of power. If you were to go to a higher capacity (say 146 GB, 15.5K) 4 Gbit Fibre Channel disk, you could double your capacity with a slight performance boost -- assuming that you're not doubling or aggregating the rate of I/Os to the disk via consolidation while reducing power from 18.74W to 17.44W. Keep in mind: When consolidating storage to larger capacity disk drives, you need to avoid aggravating performance bottlenecks.
A sampling of what vendors are doing:
Other vendor approaches include 3PARdata Inc. buying carbon offset credits to compliment its thin provisioning or storage management virtualization capabilities. Other vendors including Copan Systems, Hitachi Global Storage Technologies (HGST) (disk drive manufacturer) and NEC Corp. have either implemented or made statements of direction around power management schemes ranging from intelligent multistep power management to simply power disk drives off to avoid power consumption.
Additional things you can pursue to address cooling and power issues in your environment include:
Contrast the various approaches, and you be the judge as to what is applicable for your specific needs separating marketing "green wash" from approaches and solutions that can be deployed into your existing environment with realistic return on investment. Bottom line: There are many challenges and issues around power and cooling, and a diverse number of solutions and approaches. The best one for you will be the one that meets your specific requirements and may vary by location, application service level needs, as well as a ratio of servers to storage among other items.
You can also learn more about power and cooling, and the electrical power generating and transmission industry andrelated topics at http://www.greendatastorage.com.
About the author: Greg Schulz is founder and senior analyst with the IT infrastructure analyst and consulting firm StorageIO Group. Greg is also the author and illustrator of "Resilient Storage Networks" (Elsevier) and has contributed material to "Storage" magazine and other TechTarget venues.
17 Jul 2007
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