University of Warsaw
In this paper, the authors consider the scenario where multiple clusters of virtual machines (i.e., termed virtual clusters) are hosted in a cloud system consisting of a cluster of physical nodes. Multiple Virtual Clusters (VCs) cohabit in the physical cluster, with each VC offering a particular type of service for the incoming requests. In this paper, VM consolidation, which strives to use a minimal number of nodes to accommodate all VMs in the system, plays an important role in saving resource consumption. Most existing consolidation methods proposed in the literature regard VMs as ''Rigid'' during consolidation, i.e., VMs' resource capacities remain unchanged.