Optimal Resource Allocation for Disaster Recovery

Two key elements in disaster recovery are backing up data at remote sites and reliability of services by virtualization. To support operational services and to speed up recovery process, resources should be distributed fairly and efficiently. Thus, we discuss resource allocation algorithms to support remote data storage and live virtual machines (VMs) migration. We identify two opposing forces: on the one hand, backup data should be stored as close as possible to the original site to guarantee high access speed and to minimize network load. On the other hand, upon a site failure, VM migration should minimize the impact of resuming VMs on other sites, to protect application performance and to reduce VM restoring time. We present optimal algorithms trading-off these two contrasting goals, and we compare their performance for different network topologies and resource distributions among sites.