HyBuM: Energy-Efficient Hybrid Mobile Storage Systems using Solid States and Buffer Disks

High performance and energy-efficient storage systems are essential for mobile dataintensive applications such as remote surgery and mobile data center. Existing mobile storage systems consist of an array of independent small form factor hard disks connected to a host by a storage interface in a mobile computing environment. Although hard disks are cost-effective and can provide huge capacity and high-throughput, they have some intrinsic limitations such as long access latencies, high annual disk replacement rates, fragile physical characteristics, and energyinefficiency. Compared with hard disk drives, solid-state disks (SSD) are much more energyefficient, and can offer much faster access times. A major concern on current solid-state disk is its relatively higher price. In this paper, we developed hybrid energy efficient mobile disk architecture SBUD that integrates an array of solid-state disks with buffer disks and an array of mobile disks. The most recently used data will be cached in the solid state disks, the second most popular data will be stored in the buffer disks, and the least used data sets will be stored in the mobile disk array. Experimental results demonstratively show that SBUD provides significant energy saving for mobile storage systems such as laptops, mobile phones, and PDA compared non-hybrid architecture.