LayerMover: Storage Migration of Virtual Machine across Data Centers Based on Three-Layer Image Structure

摘要

Live Virtual Machine (VM) migration across data centers is an important support technology which will bring benefits to both cloud providers and users. At present, VM storage migration becomes the bottleneck of this technology as it explores only the static data feature of image files without much consideration on data semantics. In this paper, we propose a new space-efficient VM image structure-three-layer structure. According to different functions and features, the data of a VM are separated into an Operating System (OS) layer, a Working Environment (WE) layer, and a User Data (UD) layer. On basis of three-layer image structure, we design a novel VM storage migration system-LayerMover. It tries to improve the migration performance through optimizing current data deduplication methods. To evaluate the potential performance gains of LayerMover, we explore the similarity features of WE layer data. Our experimental results show that the similarity ratio between different images can reach 70%. Our experiments about the VM storage migration performance of LayerMover show that it can be 27% faster than current migration methods for twolayer image structures under our experimental environments. When migrating a VM in a second round or migrating a batch of VMs, LayerMover will see more performance improvement.