Live Migration of Virtual Machine with Pre-Record and Use PDoPMP to Analyse Memory Access Trend

Abstract

The virtual machine (VM) live migration could achieve VM redistribution among distributed system hosts without reducing normal working performance. Post-copy is one of the wildly used VM live migration algorithm and has lots of advantages, such as less total migration time, less downtime, lower network overhead and so on. Its disadvantage is that the VM will be suspended frequently due to the page faults caused by the incomplete memory while VM is restored to run on destination host, which may lead to an extremely negative affect on VM work efficiency. To solve this problem, this paper proposes the pre-record algorithm. Pre-record extends the VM execution on source host, records the accessed memory pages during this period to obtain pre-recorded page set (PPS), and preferentially completes the migration of PPS to avoid page faults as much as possible. It also proposes PDoPMP algorithm to analysis the trend of the trajectory of memory address in PPS, in order to further expand the predict range of memory pages. The experimental results show that the pre-record has better efficiency than traditional post-copy, especially after combining with PDoPMP. It could obviously reduce the page faults number and then the total VM migration time without prolonging the downtime, and could improve VM migration efficiency under different workload and network conditions.