On the classification and quantification of server consolidation overheads

Virtualization technology is important for servers that compose cloud data centers. The current trend is to consolidate servers to manage them easily and reduce hardware and power consumption in data centers. However, performance degradation is inherent to virtualization technology and is caused by the hypervisor and overhead due to the consolidation of several virtual servers inside a physical server. Several ways exist to virtualize a server; these methods are based mainly on virtual machines and containers. In this paper, we propose a general method to estimate the value of the consolidation overhead classes, regardless of the virtualization platform, server characteristics and workload type. We conducted several experiments in different scenarios to illustrate the usefulness of the proposed method. The results show the applicability of the proposed method and indicate that these inherent overheads are not negligible in many cases depending on, first, the type of hypervisor and, second, the hardware resources features of the physical server.