Abstract: Cloud computing is essential in the field of modern computing systems, where cloud providers have to provide effective resource for the users to increase the quality of service. A data centre consists of a large number of servers or hosts which are the key factor of cloud environment. The use of the enormous amount of computing and data centres generally leads to consumption of large amount of energy Therefore, the datacentre resources have to be distributed such that energy efficiency is maximized. The present paper surveys various resource allocation strategies and methods that are efficient in terms of energy. These strategies have been compared on the basis of their techniques. We analyse the most promising existing research in resource management and examine monitored values, supported application classes and the most important criteria for evaluating the effectiveness of the approach. It discusses methods to evaluate and model the energy consumed by these resources, and describes techniques that operate at a distributed system level, trying to improve aspects such as resource allocation.

Keywords: Cloud computing, energy efficiency, resource allocation.