Cache Effect for Power Savings of Large Storage Systems with OLTP Applications

The power consumption of modern datacenters is increasing rapidly. Storage in datacenter consumes much power. Today, databases, especially those for OLTP, have become a major storage application in datacenters. Therefore, power-saving management for OLTP applications has become an important task for user budgets and datacenter operations. This paper presents a description of a novel power-saving method for large storage systems based on application I/O behavior of OLTP applications. Features of our approach are (i) measurement of actual RAID storage power consumption, (ii) analysis of I/O behavior characteristics of OLTP applications, and (iii) delayed write operation at a storage cache level based on the I/O behavior of OLTP applications. We present a measured result of power consumption of storages during an OLTP application is running, and simulations results of our power-saving methods with varying cache size of storage, which demonstrate that our method provides substantially lower storage power consumption than that of a conventional OLTP environment.