Continuous data replication

A computer program product for use in replication comprising:

• a non-transitory computer readable medium encoded with computer executable program code for replication of data, the code configured to enable the execution of:
• quiescing IO commands to sites of an ACTIVE/ACTIVE storage system, the active/active storage system having at least two storage sites communicatively coupled via a virtualization layer;
• wherein the virtualization layer enables the at least two storage sites to present a same virtual volume at each of the at least two storage sites enabling transparent migration of a virtual machine between the at least two storage sites;
• wherein the virtualization layer enables cache coherency between each of the at least two storage sited;
• wherein the virtualization layer enables simultaneous, active/active, concurrent read/write access to the same virtual volume at both of the sites;
• creating a change set for the same virtual volume;
• unquiescing IO commands to the sites;
• transferring data of the change set to the other sites of the active/active storage system by the virtualization layer, and
• flushing the data to the sites;
• wherein flushing of the data of the change set enables the other sites of the at least two storage sites to synchronize changed data of the site from which the change set was transferred enabling the at least two storage sites to have a point in time with the same data.