Reclaiming data space by rewriting metadata

摘要

Reclaiming data space by rewriting metadata is disclosed. It is determined that fewer than all of the previous version data included in a write is required to be retained, e.g., beyond a continuous data protection window. A metadata record associated with the write is modified to point only to those blocks in which previous version data that is still required to be retained is stored. Other blocks become eligible for reclamation.