A consistency group is an optional container for FlashCopy mappings, Global Mirror
relationships, and Metro Mirror relationships. When you use a consistency group, you can complete
copy operations on the entire group instead of the individual mappings.
You can add many mappings or relationships to a consistency group. Review and consider the
following guidelines:
- FlashCopy mappings, Global Mirror relationships, and Metro Mirror relationships cannot exist in
the same consistency group.
- Relationships can be added to consistency groups if the state of the relationship matches the
state of the consistency group.
- To enable consistency protection for a consistency group, consistency
protection must be enabled on each relationship within that consistency group.
For example, if a
consistency group consists of four Metro Mirror relationships that are
configured with secondary change volumes, the data of the entire consistency group can be protected
during resynchronization. However, if a secondary change volume is not configured on one of the Metro Mirror relationships, consistency
protection is lost for all of the relationships within the consistency group.