HP XP P9000 Continuous Access Synchronous for Mainframe Systems User Guide

Figure notes:
• RAID Manager manages the consistency group on all primary and secondary systems. Business
Continuity Manager cannot be used with multiple systems.
• Open and mainframe primary volumes (P-VOLs) receive I/O requests from their applications
at the primary (main) site, and data in the volumes is updated.
• Continuous Access Synchronous or Cnt Ac-S Z runs the copy operation in the consistency
group.
• When the open or mainframe host system guarantees the update order, then data consistency
in P-VOLs and S-VOLs is insured. When the host system does not guarantee update order,
data consistency is not insured.
Consistency group requirements
Requirements are provided for the following consistency group configurations.
• “Consistency group between one main and remote system” (page 41)
• “Consistency group between multiple main and remote systems” (page 42)
Consistency group between one main and remote system
• A consistency group is configured on the main and remote system.
• When you have multiple pairs in the same consistency group, they must exist between the
same main and remote system.
• A pair can be assigned to only one consistency group.
• Continuous Access Synchronous pairs can be in the same consistency group as Cnt Ac-S Z
pairs. Use the same consistency group number for both types.
• A consistency group can have 8,192 pairs, maximum.
• One primary and one secondary system can have 128 consistency groups, maximum.
• The number for a new consistency group must be an unused number.
• If you use BCM to resynchronize a Cnt Ac-S Z pair in an open/mainframe consistency group
with one primary and secondary system, all pairs in the mainframe portion of the consistency
Consistency group planning 41