Exploiting Replication for Energy Efficiency of Heterogeneous Storage Systems

As a result of immense growth of digital data in the last decade, energy consumption has become an important issue in data storage systems. In the US alone, data centers were projected to consume $4 billion (40 TWh) yearly electricity in 2005. This cost had reached to $10 billion (100 TWh) in 2011, and expected to be around $20 billion (200 TWh) in 2016 by doubling itself every 5 years. In addition to the economic burden on companies and research institutions, these large scale data storage systems also have a negative impact on the environment. According to the EPA, generating 1 KWh of electricity in the US results in an average of 1.55 pounds of carbon dioxide emissions. Considering a projected 200 TWh energy requirement for 2016, energy-efficient data storage systems can have a huge economic and environmental impacts on society. This project exploits replication and heterogeneity existing in modern multi-disk storage systems and proposes an energy-efficient and performance-aware replica selection technique to reduce the energy consumption of data storage systems without negatively affecting their performance. Our proposed technique exploits the difference between active and idle energy consumption in heterogeneous disks holding the same replica and selects replicas by balancing energy and performance.