If you want to perform remote copy operations between more than one primary storage system and more than one secondary storage system, you must register journal groups in extended consistency groups (abbreviated as EXCTG). To register journal groups in extended consistency groups, use the EXCTG Operation window.
•Displaying the EXCTG Operation window (see section EXCTG Operation Window)
•Registering journal volumes in an extended consistency group (see the next section)
•Removing journal volumes from an extended consistency group (see section Removing Journal Groups from an Extended Consistency Group)
Registering Journal Groups in an Extended Consistency Group
If you want to perform remote copy operations between more than one primary storage system and more than one secondary storage system, you must register journal groups in an extended consistency group, which is abbreviated as EXCTG.
•Notes on configuring an extended consistency group:
You must confirm that the journal groups to be registered must be in Active or Stop status.
You must not register master and restore journal groups in the same extended consistency group.
•Configuring primary EXCTG:
You need to configure a primary EXCTG, because the primary EXCTG will be necessary if you need to reverse the primary and secondary sites after a failure occurs. If you reverse the copy direction when no primary EXCTG is configured, data update sequence will be maintained on journal group basis, but not on extended consistency group basis.
For details on reversing copy direction, see section Transferring Operations Back to the Primary Site.
•Configuring secondary EXCTG:
You need to configure a secondary EXCTG when you use more than one primary storage system and more than one secondary storage system. URz uses the secondary EXCTG to maintains data update sequence of master journal groups that are paired with restore journal groups in secondary EXCTG. If no secondary EXCTG is configured, data update sequence will not be maintained, and data consistency will not be maintained between the primary storage systems and the secondary storage systems.
To register journal groups in an extended consistency group:
Chapter 7 Using Extended Consistency Groups |
