Dell PowerFlex 4.6.x Technical Overview

Activating or terminating a replication consistency group

When a replication consistency group is active, replication is enabled. When a replication consistency group is inactive, replication is stopped and changes are not tracked, but the replication consistency group maintains its configuration.

By default, a new replication consistency group is created as active. You may, however, specify that it be created in the inactive state.

When the replication consistency group is in an inactive state, replication is stopped and the journal capacity is released. The I/Os are handled by the SDS and not the SDR and no journal capacity is consumed. All replication consistency group configurations are maintained, including source and target roles, pair configuration, and volume access modes.

The replication consistency group can be terminated automatically by the system when the journal capacity is fully consumed. You can also manually inactivate the replication consistency group using the terminate command. When the replication consistency group is terminated, volume I/Os bypass the SDR and go directly to the SDS. You can terminate the replication consistency group at both sites separately. Alternatively, you can terminate the replication consistency group at one site; once connectivity is restored, the peer will automatically terminate the replication consistency group at the other site.

Failover can be performed when the replication consistency group is inactive, however consider that the data at the target may be old. While in failover mode, mappings at both the source and target can be activated and volumes can be written to, just like when the replication consistency group is in an active state. There is no data synchronization when the replication consistency group is inactive. You can activate the replication consistency group only once it is no longer in failover mode.

The active or inactive replication consistency group state and the commands to terminate or activate a replication consistency group are only available if both peer systems are running PowerFlex v3.6.x or later.