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 appear 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.