Patent ID: 7769723

Claim:
A method for providing continuous data protection in a file system, comprising: generating one or more persistent consistency point images (PCPIs) of the file system, wherein each PCPI shares one or more file system blocks with at least one other generated PCPI; executing a consistency point during which data changes contained in memory are flushed to persistent storage and one or more data blocks on the persistent storage are freed; performing write allocation of the freed blocks to a delete log to prevent the freed blocks from being reclaimed for reuse by the file system; allowing any of the freed blocks that are subsequently freed from the delete log to be reclaimed by the file system for reuse during future write allocation; updating a consistency point log to list blocks which have been freed during execution of the consistency point, wherein the consistency point log comprises a header and at least one entry for each consistency point logged in the consistency point log; and appending a new entry to the consistency point log and updating the header of the consistency point log.