“…Energy efficient hardware techniques usually employ the energy efficient computing components [19], [20], such as, multispeed disks, SSD disks, DVFS enabled CPU and Flash memory etc. From the layer of cloud system perspective, energy efficient techniques are employed in different layers, such as, in application layer [21], data center layer [22], [23], cluster layer [24], [25], RAID layer [26], [27], node layer [28], virtualization layer [29], [30], OS layer [31], processor layer [32], [33], disk layer [34], [35], memory layer [36], [37] and network layer [38], [39]. The review map of the different energy-aware techniques is shown in Figure 2.…”