Understanding the effects of hypervisor I/O scheduling for virtual machine performance interference

In virtualized environments, the customers who purchase virtual machines (VMs) from a third-party cloud would expect that their VMs run in an isolated manner. However, the performance of a VM can be negatively affected by co-resident VMs. In this paper, we propose vExplorer, a distributed VM I/O performance measurement and analysis framework, where one can use a set of representative I/O operations to identify the I/O scheduling characteristics within a hypervisor; and potentially leverage this knowledge to carry out I/O based performance attacks to slow down the execution of the target VMs. We evaluate our prototype on both Xen and VMware platforms with four server benchmarks and show that vExplorer is practical and effective. We also conduct similar tests on Amazon's EC2 platform and successfully slow down the performance of target VMs.