Data Change Map DCM

DCM is a type of log that is associated with the data volumes under the RVG. Each bit in the bitmap represents a region of data on the data volume, and indicates whether the region has been modified on the Primary but not updated on the Secondary. The region size is computed internally, based on the volume size. DCM can be used when the Replicator Log is full or to mark the changed block due to updates when auto synchronization is in progress.