A Comprehensive Review of Cloud Computing Virtual Machine Consolidation

In the last decade, users have been able to access their applications, data, and services via the cloud from any location with an internet connection. The scale of heterogeneous cloud environments is continuously growing due to the development of computing-intensive smart devices. The cloud computing system is managed by a data center, which consists of physical machines (PMs) or servers and software-based emulation of PMs called virtual machines(VMs). The deployment of a huge number of physical servers as a result of the exponential development in demand for cloud services has resulted in high energy consumption and ineffective resource usage. Efficient utilization of resources and minimizing power consumption in any data center have become crucial challenges. Virtual machine consolidation (VMC) is a method of optimizing computing resources by consolidating multiple VMs onto a reduced number of PMs. By consolidating VMs and running fewer physical servers, VM consolidation can reduce power consumption and improve resource utilization. This review paper presents a comprehensive analysis of cloud computing virtual machine consolidation, exploring various strategies, benefits, challenges and future trends in this domain. By examining a wide range of literature from the year 2015 to 2023, this review attempts to provide insight into the current state of VM consolidation and its possible effects on the performance and sustainability of cloud computing. The main flaw in the articles is that the various authors focused on different assessment metrics when the emphasis should have been on increasing cloud system service quality and energy efficiency. Future research can be aimed at developing a multi-objective system that emphasizes minimizing cloud energy usage without sacrificing service quality and preventing service level agreements with cloud users from being compromised.