US Patent 10083057 Migration of active virtual machines across multiple data centers

A method of providing migration of active virtual machines by performing data migrations between data centers using distributed volume and stretched cluster mechanisms to migrate the data synchronously within the distance and time latency limits defined by the distributed volume protocol, then performing data migrations within data centers using local live migration, and for long distance data migrations on a scale or distance that may exceed synchronous limits of the distributed volume protocol, combining appropriate inter- and intra-site data migrations so that data migrations can be performed exclusively using synchronous transmission.