Dell PowerFlex Appliance with PowerFlex 3.x Administration Guide

Remote consistency group (RCG)

Remote consistency group (RCG) is an entity that includes a set of consistent volume pairs. The volume on the source from a single protection domain (PD) is replicated to a remote volume from a single PD on the target. This creates a consistent pair of volumes.

When replication is first activated for an RCG, the target volumes will be synchronized with the source volumes. For each volume pair, the entire contents of each source volume are copied to the corresponding target volume. When there is more than one volume pair in the RCG, the order in which the volumes are synchronized is determined by the order in which the volume pairs were created. The initial synchronization occurs while all applications are running and performing I/O. Any writes to an area of the volume that has already been synchronized will be sent to the journal. Writes to an area of the volume that has not already been synchronized will be ignored, as the updated content will be copied over eventually as part of the synchronization.

The initial synchronization can also take place while the system is offline, however the application I/O must first be paused. You can add and manage RCG on both the source and target systems.