HP XP P9500 Storage - Manual (Page 40)

5 Performing pair operations
This chapter provides instructions for performing BC 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 operations.
•
“Check pair status” (page 40) . 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 40) , 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 45) .
•
“Pair split” (page 45) , 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 consistency group pair-split workflow” (page 47) ,
which allows you to split pairs in a consistency group at a specified time.
•
“Pair resynchronization” (page 48) , in which the S-VOL is again updated from the P-VOL.
•
“Pair deletion” (page 51) 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 53) .
•
You should also check whether an operation is possible given the status of related L1 and L2
pairs. For information, see
“Status for L1, L2 pairs and operations permitted” (page 55) .
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.
You can create cascaded pairs; instructions are included for L1 and L2 pairs.
Related information
•
“Prerequisite information for creating pairs” (page 41)
•
“Creating pairs” (page 43)
40 Performing pair operations