US Patent 11334450 Backup method and backup system for virtual machine

A backup method and a backup system for virtual machines are provided. A first virtual machine management module replicates data of a write IO request of a first virtual machine to generate replication data, and the write IO request is configured to request a data write operation to a disk of the first virtual machine. The first virtual machine management module transmits the replication data to a second virtual machine management module while the first virtual machine is running. The second virtual machine management module receives the replication data and controls or performs a data write operation to a disk of the second virtual machine of the second virtual machine management module according to the replication data. When the first virtual machine is paused, the second virtual machine management module performs a snapshot operation on the disk of the second virtual machine to generate snapshot data.