Patent ID: 7685386

Claim:
A system for data storage resynchronization comprising: a primary site comprising; a primary server; a primary storage unit; a primary replication agent; and a primary storage controller writing data to one or more primary pages on said primary storage unit upon receiving a command to do so from said primary server; a secondary site comprising; a secondary server; a secondary storage unit; a secondary replication agent receiving a command from said primary replication agent to write said data at said secondary site ; and a secondary storage controller writing said data to one or more secondary pages on said secondary storage unit upon receiving a command to do so from said secondary replication agent, said secondary storage controller retrieving page-change indicators from said secondary pages and transmitting said page-change indicators to said primary controller, wherein said secondary pages correspond to said primary pages; and means for comparing said retrieved page-change indicators of said secondary pages against page-change indicators of said corresponding primary pages, said comparing means sending said primary page to said secondary replication agent for replacement of said corresponding secondary page at said secondary site where page-change indicators of said corresponding pages do not match.