What Is a Consistency Group?
A consistency group is a collection of remote replications that have a service relationship with each other. You can simultaneously synchronize, split, or perform a primary/secondary switchover for all the remote replications in a consistency group.
In medium- and large-sized database applications, data, logs, and modification information are stored on different LUNs. When data on one of the LUNs is unavailable, data on the other LUNs is also invalid. If remote disaster recovery needs to be implemented for these LUNs simultaneously, time consistency between multiple remote replications must be considered. The consistency group function provided remote replication ensures that multiple LUNs are consistent regarding the time.