HP XP P9000 Continuous Access Synchronous for Mainframe Systems User Guide

Priority is determined within the range of the number of initial copy operations performed at the
same time. Therefore, until the first initial copy operations complying with the order of the Priority
are completed, the additional initial copy operations are not started.
Consistency group planning
Consistency groups allow you to perform one operation on all pairs in the group. Consistency
groups also ensure that all pairs are managed in a consistent status.
You determine which pairs to include in a particular consistency group. This is based on business
criteria for keeping status consistent across a group of pairs, and for performing specific operations
at the same time on the group.
• A consistency group can consist of the pairs in one main and one remote XP P9500, or pairs
in multiple main and remote XP P9500s.
• Both Cnt Ac-S and Cnt Ac-S Z pairs can belong to the same consistency group.
Consistency group for pairs in one main and one remote XP P9500
Cnt Ac-S and Cnt Ac-S Z pairs between one main and remote system can be placed in the same
consistency group, as shown in the following figure.
Figure notes:
• Cnt Ac-S pairs are assigned to a consistency group using RAID Manager.
Cnt Ac-S Z pairs are assigned to a consistency group using Business Continuity Manager
(BCM).
• Open and mainframe volumes (primary or main volumes) receive I/O requests from their
applications at the primary (main) site, and data in the volumes is updated.
• Cnt Ac-S or Cnt Ac-S Z runs copy operations in the consistency group.
Consistency group for pairs in multiple primary and secondary systems
Cnt Ac-S and Cnt Ac-S Z pairs in multiple primary and secondary systems can be placed in the
same consistency group. A maximum of four storage system pairings can be placed in the same
consistency group.
40 Planning for Continuous Access Synchronous Z