Patent ID: 7720801

Claim:
A storage system for improving efficiency of a transmission of data identifiers, comprising: an operating system of the storage system configured to record, in a log, entries of incremental changes of data occurring between a first persistent consistency point image (PCPI) and a second PCPI; a mirror update transmission cycle of the first and the second PCPI wherein one or more of the incremental changes of data occurring between the first and the second PCPI are transmitted to a destination mirror; a first set of one or more data identifiers in the log entries configured to reference incremental changes of data that have been allocated and then deleted between the first and the second PCPI; a second set of one or more data identifiers in the log entries configured to reference incremental changes of data that have not been allocated and then deleted between the first and the second PCPI; a processor operatively connected to the storage system configured to scan the log entries to determine the data identifiers of the first set of data identifiers and further con-figured to determine the data identifiers of the second set of data identifiers; and a changed data function, in response to the scan of the log, configured to omit from the transmission of the mirror update transmission cycle to the destination mirror, the data identifiers of the first set of data identifiers that have been determined by the scan of the log to have been allocated between the first and the second PCPI and then deleted between the first and the second PCPI, wherein the changed data function does not omit from the transmission of the mirror update transmission cycle to the destination mirror the data identifiers of the second set of data identifiers.