Patent ID: 7647462

Claim:
A method for data synchronization, comprising: for each portion of data at a primary volume in a primary storage device and each portion of corresponding data at a secondary volume in a secondary storage device, determining a first identifier for a portion of data at the primary volume, wherein a unique identifier is associated with each portion of data at the primary volume, wherein the first identifier for the portion of data at the primary volume is generated whenever the portion of data at the primary volume is updated; determining a second identifier for a portion of corresponding data at the secondary volume, wherein a unique identifier is associated with each portion of data at the secondary volume, and the second identifier for the portion of corresponding data at the secondary volume is generated whenever the portion of corresponding data at the secondary volume is updated; comparing the first and second identifiers; and in response to determining that the first and second identifiers do not match, replacing the portion of corresponding data at the secondary volume in the secondary storage device that stores data with the portion of data at the primary volume.