a client transitions between a suspended virtual machine state and an active vm state by employing a working set comprising a vm state file and a working set index file . the vm state file serializes each of the vm components that is saved to storage . the working set index file contains indirect information that records the offset , length , and region of various pieces of the vm state and contains a vm working set . the vm suspend state serialization is implemented as either a monolithic or an incremental process .