Methods, systems, and computer program products for tracking updates during memory migration. The method includes computer instructions for establishing communication from a source virtual machine to a target virtual machine, the source virtual machine including a memory. Contents of the memory on the source virtual machine are transmitted to the target virtual machine. The contents include a plurality of pages. Pages in the memory that are modified subsequent to being transmitted to the target virtual machine are tracked. The tracking includes creating a data structure having a plurality of bits corresponding to the pages in the memory, the bits indicating if the corresponding pages have been modified subsequent to being transmitted to the target virtual machine. The data structure also includes a first bit location index to identify the location of the first bit in the data structure that corresponds to a modified page. Bits in the data structure are updated in response to detecting that the corresponding pages have been modified subsequent to being transmitted to the target virtual machine. The data structure is scanned starting at the first bit location index to identify pages that have been modified subsequent to being transmitted to the target virtual machine. The identified pages are transmitted to the target virtual machine.