iShare: Balancing I/O performance isolation and disk I/O efficiency in virtualized environments
Song Wu, Songqiao Tao, Xiao Ling, Hao Fan, Hai Jin, Shadi Ibrahim · Concurrency and Computation Practice and Experience · 2015
Summary Performance isolation has long been a challenging problem for disk resource allocation in virtualized environments. While there have been many researches working on I/O performance isolation and disk utilization, none of them addresses the I/O performance isolation and disk utilization as a whole. To this end, we investigate the impact of current disk I/O performance isolation schemes on disk I/O utilization. Interestingly, our studies report that current isolation schemes bring unnecessary disk idle and reduce the overall disk I/O performance because of ignoring the disk states and characteristics of requests. Accordingly, we propose an adaptive proportional‐share I/O scheduling framework, namediShare, in virtualized environments.iSharenot only ensures I/O performance isolation through proportionally allocating time slices according to the weights of virtual machines but also preserves high disk efficiency by detecting disk states and adaptively adjusting the time slice size based on characteristics of requests. We implement a prototype ofiShareon the Xen platform. The experimental results show thatiShareensures I/O performance isolation while improving disk I/O efficiency, compared withBlkio(i.e., the default I/O performance isolation method in Xen),iShareincreases disk I/O bandwidth by 58% and slightly improves the I/O performance isolation for the sequential write applications. Copyright © 2015 John Wiley & Sons, Ltd.