Working Set-based Physical Memory Ballooning

Minimizing the total amount of physical memory consumption of a set of virtual machines (VM) running on a physical machine is the key to improving a hypervisor’s consolidation ratio, which is defined as the maximum number of VMs that can run on a server without any performance degradation. To give each VM just enough physical memory equal to its true working set (TWS), we propose a TWS-based memory ballooning mechanism that takes away all unneeded physical memory from a VM without affecting its performance. Compared with a state-of-the-art commercial hypervisor, this working setbased memory virtualization technique is able to produce noticeably more effective reduction in physical memory consumption under the same input workloads, and thus represent promising additions to the repertoire of hypervisor-level optimization technologies.