Patent ID: 8935502
Filing Date: 2015-01-13
Classification: G06F

Abstract:
1. A method comprising: recording, by a virtual machine monitor executed by a processing device, a source-generation count representing content on a source disk associated with a virtual machine; recording a writes-mirrored value representing content on a destination disk migrated from a source disk, at a time contents of the source disk and the destination disk were equal; recording a flush-request value representing the source-generation count at a time a flush is requested by a guest operating system of the virtual machine; recording a writes-flushed value representing the writes-mirrored value at a time of a last flush of the destination disk; identifying, by the virtual machine monitor, a steady state wherein contents associated with a virtual machine stored on the source disk and a destination disk are equal; upon identifying the steady state, setting a writes-mirrored value to the recorded source-generation count; determining if a flush request to flush the source disk has been issued by the guest operating system of the virtual machine; setting the flush-request value to the source-generation count at a time of the flush request; and flushing the destination disk upon determining that the flush-request value is greater than the writes-flushed value and the flush-request value is less than or equal to the writes-mirrored value.