Ensuring consistency of replicated volumes

A system for use in ensuring consistency of dynamically changing volumes, the system comprising:

• a computer having a memory;
• computer-executable program code operating in memory, wherein the computer-executable program code is configured for execution of the following steps:
• creating a production change map for at least part of a first volume;
• wherein the production change map is marked to represent pending IO to be applied to the at least a part of the first volume;
• creating a replication change map for at least a part of a second volume;
• wherein the replication change map is marked to represent pending IO to be applied to the at least a part of the second volume;
• calculating a first signature corresponding to a portion of the at least a part of the first volume;
• wherein the portion of the first volume selected for the calculation of the first signature is chosen to not include the portion marked as pending IO in the production change map;
• transferring the first signature from the first volume to the second volume;
• comparing the first signature to a second signature, the second signature corresponding to a portion of the at least a part of the second volume corresponding to the portion of the first volume;
• wherein portions marked as pending in the replication change map are not included in calculation of the second signature.

A program product comprising:

• a computer-readable storage medium encoded with computer-executable program code enabling:
• computer-executable program code operating in memory, wherein the computer-executable program code is configured for execution of the following steps:
• creating a production change map for at least part of a first volume;
• wherein the production change map is marked to represent pending IO to be applied to the at least a part of the first volume;
• creating a replication change map for at least a part of a second volume;
• wherein the replication change map is marked to represent pending IO to be applied to the at least a part of the second volume;
• calculating a first signature corresponding to a portion of the at least a part of the first volume;
• wherein the portion of the first volume selected for the calculation of the first signature is chosen to not include the portion marked as pending IO in the production change map;
• transferring the first signature from the first volume to the second volume;
• comparing the first signature to a second signature, the second signature corresponding to a portion of the at least a part of the second volume corresponding to the portion of the first volume;
• wherein portions marked as pending in the replication change map are not included in calculation of the second signature.