US Patent 10437865 Computer storage deduplication

Decentralized deduplication operations in a virtualized computer environment having multiple storage devices employ a hash index for each storage device. When an image of a virtual machine is selected to be migrated from a source storage device to a destination storage device, hash values representing content of the storage blocks of the virtual machine are compared with hash entries of the destination hash index. Storage blocks of the virtual machine that have matching hash entries in the destination hash index are not transferred as part of the migration process so that the overall migration process can be accelerated.