1. An apparatus for managing autonomous third party data transfers between a source storage device and a destination storage device, comprising: a determination module configured to determine a segment size for an autonomous data transfer, the segment size based on a data capacity of a data mover conducting the autonomous data transfer, ans selected such that each segment ends on a block boundary of the destination storage device; a segmenter configured to divide the autonomous data transfer into segments according to the segment size; and an execution module configured to execute an autonomous data transfer for each segment.