Energy conservation is all about saving energy, and within data centers storage is one of the biggest energy hogs driving ever increasing energy costs. So how do you know which storage solution is really the most energy efficient? How do you penetrate the fog of greenwash and get usable, competitive energy consumption numbers? The answer is standards, and the one group that is driving standards for storage network products is the Green Storage Initiative (GSI) Team within the Storage Network Industry Association, SNIA.
A draft publication, the “SNIA Green Storage Power Measurement, Technical Specification”, is the latest attempt to establish a standardized methodology that enables accurate and comparable measurements of the power consumption of commercial storage systems. This objective, metric-based approach should enable the user community to demand that vendors supply energy consumption data that can be used to contrast competitive solutions and effectively eradicate or at least minimize vendor market speak. Note this is still a draft document and as such is not yet a practical reality, but it is heading in the right direction.
The GSI group have developed frameworks for six broad taxonomy categories. Online, Near-Online, Removable Media, VTL, Infrastructure Appliance, and Infrastructure Interconnect Elements. Within these frameworks are the guidelines for measurements and data collection including the metrics and most importantly how to audit, verify and publish the measurements.
Metrics
The metrics proposed by GSI are designed to evaluate the energy impact of storage network products. The initial metrics focus on idle power measurements, a future intent is to include active devices.
Average Idle Power (P) = sum of the sample power measurement (W) / number of sample measurements (N)
SNIA Idle Power Metric = Capacity of the storage unit/ Average Idle Power
Action Item: While this may be a basic metric, it is a standardized format and should be useful when comparing competitive storage solutions. As a tool for storage buyers, its usefulness will increase significantly as it matures to include active devices. The primary beneficiary of this standard is the end-user. Storage purchasers should pressure vendors to ensure universal support and willingness to implement this standard and push SNIA to make this a readily accessible standard.
Footnotes: SNIA Green Storage Power Measurement Specification, Jan 20th, 2009