虚拟机全系统在线迁移  

Whole-System Live Migration Mechanism for Virtual Machines

作　　者：张彬彬[1] 罗英伟[1] 汪小林[1] 王振林 孙逸峰[1] 陈昊罡[1] 许卓群[1] 李晓明[1] 

机构地区：[1]北京大学信息科学技术学院,北京100871 [2]美国密歇根理工大学计算机科学系,美国密歇根49931

出　　处：《电子学报》2009年第4期894-899,共6页Acta Electronica Sinica

基　　金：国家973重点基础研究发展规划(No.2007CB310900);国家自然科学基金(No.90718028,No.60873052);国家863高技术研究发展计划(No.2008AA01Z112);教育部-英特尔信息技术专项科研基金(No.MOE-INTEL-08-09);华为科技基金(No.YJCB2007002SS)

摘　　要：本文介绍了一种虚拟机全系统在线迁移方法.设计了三阶段迁移方案(Three-Phase Migration,TPM),能迁移包括外存数据在内的虚拟机全系统状态,最小化迁移过程中的虚拟机暂停时间,并保证数据的一致性和完整性.在该方案中,使用了基于Block-bitmap的外存同步方式,由Block-bitmap记录迁移过程中的外存更新.此外,还提出了增量迁移方案(Incremental Migration,IM),当被迁移的虚拟机需要迁移回源主机时,增量迁移能够减少需要迁移的数据量,从而缩短迁移时间,降低迁移造成的性能代价.通过在Xen上的实验表明,该全系统迁移方案即使在I/O密集型的负载情况下仍然执行得很好,迁移过程中的虚拟机暂停时间与共享外存迁移时的暂停时间接近.基于Block-bitmap的外存同步机制简单高效,其监控过程中产生的性能代价低于1%.We describe a whole-system live migration mechanism which transfers the whole run-time state including local disk storage,in this paper.A three-phase migration（TPM） algorithm is proposed to minimize the downtime caused by migrating large disk storage data and keep data integrity and consistency. A Block-bitmap is used to track all the write accesses to the local disk storage during the migration, and then to direct synchronization. Also,an incremental migration（IM） algorithm is described to facilitate the migration back to initial source machine. Our experimental study based on Xen shows that the algorithms perform well even when I/O-intensive workloads run in the migrated VM. The downtime of whole-system migration is close to shared-storage migration algorithms. The Block-Bitmap based synchronization mechanism used in both TPM and IM is simple and effective,and the performance overhead of recording all the writes is less than 1 percent.

关 键 词：虚拟机 迁移 全系统 块位图 XEN 

分 类 号：TP312[自动化与计算机技术—计算机软件与理论]