Differential Virtual Time (DVT): Rethinking I/O Service Differentiation for Virtual Machines

Date Added: Jun 2010
Format: PDF

This paper investigates what it entails to provide I/O ser-vice differentiation and performance isolation for virtual machines on individual multicore nodes in cloud platforms. Sharing I/O between VMs is fundamentally different from sharing I/O between processes because guest VM operating systems use adaptive resource management mechanisms like TCP congestion avoidance, disk I/O schedulers, etc. The problem is that these mechanisms are generally sensitive to the magnitude and rate of change of service latencies, where failing to address these latency concerns while designing a service differentiation framework for I/O results in undue performance degradation and hence, insufficient isolation between VMs.