Online virtual disk migration with performance guarantees in a shared storage environment

Abstract

In this paper, we present a novel approach of online virtual disk migration with performance guarantees, which is important for storage maintenance tasks. Our approach can be applied to moving virtual disk and exchanging virtual disks. It identifies the surplus I/O resource of storage pools after satisfying performance requirement of virtual disks with EPYFQ scheduling algorithm, and gives high priority of using these I/O resource to migration tasks. Thus, the performance of virtual disks is guaranteed during migration, and the migration is completed in the shortest possible time. Moreover, our approach divides migration task into multiple storage transactions, which can protect the consistency of the data in the migrated virtual disks when application I/O and migration I/O execute concurrently. We implement our approach into E-DM, a kernel module of Linux, and evaluate it. The result shows that the IOPS of virtual disks is decreased not more than 3% during migration. © Springer-Verlag Berlin Heidelberg 2005.