Low-bandwidth VM migration via opportunistic replay

Virtual machine (VM) migration has been proposed as a building block for mobile computing. An important challenge for VM migration is to optimize the transfer of large amounts of disk and memory state. We propose a solution based on the opportunistic replay of user interactions with applications at the GUI level. Whereas this approach results in very small replay logs that economize network utilization, replay of user interactions on a VM at the migration target site can result in divergent VM state. Cryptographic hashing techniques are used to identify and transmit only the differences. We discuss the implementation challenges of this approach, and present encouraging results from an early prototype that show savings of up to 80.5% of bytes transferred.