Technologies are described herein for utilizing shared storage for efficient VM-HA. During the replication of the state of a primary virtual machine to a replicated virtual machine hosted on a secondary host, a request from the primary virtual machine is received to write a dirty page of guest memory to a shared storage device. Upon receiving the request, replication metadata indicating the location of the page of guest memory on the shared storage device is sent to the secondary host computer causing the secondary host computer to retrieve the dirty page of guest memory from the shared storage device during synchronization instead of the dirty page of guest memory having to be copied directly from the primary virtual machine to the secondary host computer.