Manual
5 Performing pair operations
This chapter provides instructions for performing BC Z pair operations using RWC. Also included
is an operation for splitting pairs by consistency group, using RAID Manager.
Pair operations workflow
A typical workflow for performing pair operations consists of the following. You must have Storage
Administrator (Local Copy) role to perform BC Z operations.
• “Check pair status” (page 37). Each operation requires a pair to have a specific status. You
also check pair status to ensure that an operation completed successfully.
• “Pair creation” (page 37), in which the S-VOL becomes a duplicate of the P-VOL. You can
create a pair and immediately split it so that you can access the S-VOL.
• “Suspending pair creation” (page 41).
• “Pair split” (page 42), which separates the P-VOL and S-VOLs and allows use of S-VOL data
by secondary applications.
• “Splitting pairs in a consistency group using At-Time Split workflow” (page 44), which allows
you to split pairs in a consistency group at a specified time.
• “Pair resynchronization” (page 45), in which the S-VOL is again updated from the P-VOL.
• “Pair deletion” (page 47) in which the pair relationship between the pair volumes is ended,
though the data remains.
Check pair status
Every pair operation requires the pair to have a specific status. When you want to perform a pair
operation, check pair status to ensure that you can proceed successfully.
• For pair status definitions and instructions for finding pair status, see “Monitoring the system
” (page 49).
• For the operations allowed for specific pair statuses, see “Status, pair operations permitted ”
(page 51).
Pair creation
When you create the initial copy, data in the P-VOL is copied to the S-VOL. During the operation,
the P-VOL can receive updates from the host. After the initial copy is completed, the updated data
in the P-VOL—differential data—is copied to the S-VOL periodically (update copy).
You can create the pair and immediately split it so that you can have instant access to the S-VOL.
Instructions are included in the procedure.
Related information
• “Prerequisite information for creating pairs” (page 37)
• “Creating pairs” (page 39)
Prerequisite information for creating pairs
• Make sure that your volumes are set up for pairing. For more information, see “Planning pair
volumes” (page 15).
• Volumes should be in SIMPLEX status.
Pair operations workflow 37