Energy-Efficient Techniques for Disk-Based Mobile Systems

The usage of hard disks has been increasing in mobile systems due to popular I/O intensive applications such as multimedia players. However, significant power consumption in the disks still limits battery lifetimes of mobile systems critically. In this paper, we propose a disk replacement technique for energy-efficient mobile storage systems. We replace a single large disk with several smaller disks while preserving the capacity or area constraint of the large disk. We also introduce file placement techniques designed for mobile platforms by exploiting correlation between file requests. The proposed techniques reduce a significant amount of energy consumed by the storage systems. Experimental results show that the proposed techniques can save energy consumption by 49% when eight 1" disks are used instead of a single 2.5" disk with a reasonable delay increase while meeting the capacity constraint of the 2.5" disk.