Patent ID: 8533160

Claim:
A storage system comprising: one or more logical volumes configured to store data; and a processor configured to: produce snapshots for the logical volumes based on a pre-scheduled snapshot acquisition time, execute remote copy of difference data for the snapshots based on pre-scheduled remote copy start times, if the processor estimates that a current remote copy of the difference data of snapshots will not be completed by a next remote copy start time, re-schedule a time of one or more of a current snapshot acquisition time, a current remote copy start time, and the next remote copy start time, and if re-schedule of the time is still insufficient to permit completion of the current remote copy before the current remote copy is executed, thin out an amount of the difference data for the snapshot, wherein the processor is configured to estimate the amount of difference data for a snapshot of the logical volume acquired the current remote copy based on an amount of difference data for a snapshot of the logical volume acquired a previous remote copy, and to execute the re-scheduling based on the estimated amount of difference data.