Patent ID: 6085298
Filing Date: 2000-07-04
Classification: G06F

Abstract:
In a computing environment including a primary system having a primary mass storage device that stores a plurality of primary data blocks and a backup system having a backup mass storage device that stores a plurality of backup data blocks, a method for comparing the primary mass storage device to the backup mass storage device, comprising the steps of:calculating, by the backup system, a first digest based on a selected backup data block, the selected backup data block corresponding to a physical location within the backup mass storage device, wherein the first digest is smaller than the selected backup data block;calculating, by the primary system, a second digest based on a selected primary data block, the selected primary data block corresponding to the selected backup data block and also corresponding to a physical location within the primary mass storage device, wherein the second digest is smaller than the selected primary data block, andcomparing the second digest with the first digest to determine whether the second digest and the first digest indicate that the selected backup data block and the selected primary data block contain the same data.