HP XP P9000 Continuous Access Synchronous for Mainframe Systems User Guide

6 Pair operations
This chapter provides instructions for performing Cnt Ac-S Z pair operations.
Pair operations workflow
Basic Cnt Ac-S Z operations consist of the following tasks.
• Check prerequisites for each procedure.
• Always check pair status. Each Cnt Ac-S Z operation requires the pair to be in a specific
status.
• Create a pair, in which the S-VOL becomes a duplicate of the P-VOL.
• Suspend a pair, which separates the P-VOL and S-VOL and allows read/write access to the
S-VOL if desired.
• Resynchronize a pair, in which the S-VOL again mirrors the ongoing, current data in the P-VOL.
• Delete a pair.
NOTE: In order to perform pair operations or check the pair status, LU paths must be established.
If you intend to perform storage or replication management operations, make sure that pairs are
deleted before removing LU path definitions.
NOTE: Pair operations cannot be performed when changing the microcode, nor if microcode
changes are cancelled. If you start a microcode change, make sure it completes before performing
pair operations.
Disaster recovery procedures are discussed in “Disaster recovery” (page 104).
Checking pair status
Every Cnt Ac-S Z operation requires that the pairs have a specific status. Before performing any
operation, check pair status.
• Find status requirements under the prerequisite information for each operation.
• To view a pair’s current status in the GUI, or review status definitions, see “Monitoring pair
status” (page 74).
Creating pairs
When you create the initial copy, all data in the P-VOL on the main system is copied to the S-VOL
on the remote system. The P-VOL remains available to the host for I/O operations.
Prerequisite information
• The initial copy is performed from the main system.
• S-VOLs must be offline to all hosts.
• You will select the main and remote volumes to be paired by individual volume’s CU and/or
LDEV numbers. You should have this information on hand.
• Ports must be configured for Cnt Ac-S Z. See “Defining port attributes” (page 57) for more
information.
• The main and remote system must be configured for Cnt Ac-S Z. See “Configuring storage
systems, defining logical paths” (page 58) for more information.
66 Pair operations