Virtual machine(VM)images are frequently backed up for service reliability in datacenters.However,the duplicated data of image backups take up a large amount of storage space.Thus,deduplication technologies are often used in backup operations to save storage space by removing duplicated data.Since backup operations with deduplication are resource intensive and time consuming,how to reduce the time of backup operations has become a key issue of datacenter management.Contemporary deduplication backup strategi...