HP XP P9500 Storage - Manual (Page 54)

6 Pair operations
This chapter provides instructions for performing Continuous Access Journal pair operations.
Pair operations workflow
The basic Cnt Ac-J operations consist of the following:
•
Check pair status. Each Cnt Ac-J operation requires the pair to be in a specific status.
•
Create the pair, in which the S-VOL becomes a duplicate of the P-VOL.
•
Split the pair, which separates the P-VOL and S-VOL and allows read/write access to the
S-VOL if desired.
•
Restore the pair so that the S-VOL again mirrors the on-going, current data in the P-VOL.
•
Delete a pair, which removes the pair relationship from the volumes.
NOTE: Pair operations cannot be performed if micro exchange is in progress or if micro exchange
is suspended because the Cancel button has been pressed or because errors have occurred. If you
start a microcode change, be sure it completes before performing pair operations.
NOTE: You cannot use Remote Web Console to perform pair operations or check pair status on
volumes with LU path settings that have been canceled. Before you perform pair operations or
check the pair status, configure the LU path settings to the volume on which you want to perform
these actions.
Checking pair status
Every Cnt Ac-J operation requires that pairs have a specific status. Before performing any operation,
check pair status.
•
Find status requirements in the prerequisite information for each operation.
•
To view a pair’s current status in the GUI, or to review status definitions, see “Monitoring pair
activity and status” (page 66) .
Creating the initial copy
The pair is created when you create the initial copy. All data in the P-VOL on the primary system
is copied to the S-VOL on the secondary system. The P-VOL remains available to the host for I/O
operations.
Prerequisite information
•
The initial copy must be performed from the primary system.
•
Pair status of both data volumes must be SMPL.
•
S-VOLs must be offline to all hosts.
•
The primary and secondary systems and logical paths must be defined. See “Configuring
local and remote systems for Cnt Ac-J ” (page 45) for more information.
•
Journal volumes must be registered to the journals that are associated with pairs. See
“Registering journal volumes in a journal ” (page 50) for more information.
•
If you are creating multiple pairs at one time, you must specify the number of volumes that
initial copy operations can be performed on concurrently. See
“Specifying number of concurrent
initial/resync copies” (page 49) for more information.
54 Pair operations