HP XP Racks - Manual (Page 52)

Resynchronizing a suspended pair copies the P-VOL to the S-VOL and takes the same amount of
time as the initial copy operation.
CAUTION: Resynchronizing a pair does not ensure data consistency. Data in the two volumes
is the same only if:
•
The P-VOL is offline.
•
The pair is split (the S-VOL status is “PSUS”).
For more information about pair status, see “The RWC pair status names and descriptions”
(page 63) .
For more information about ensuring data consistency, see “Workflow for ensuring data
consistency” (page 47) .
NOTE: If you perform a Quick Restore for a pair consisting of an encrypted volume and an
unencrypted volume, the encryption statuses of the volumes are reversed.
Related topics
•
“Types of pair resynchronization” (page 52) .
•
“Workflow for resynchronizing BC pairs” (page 54) .
•
“Resynchronizing or restoring BC pairs” (page 55) .
•
“Volume pairs” (page 7) .
•
“Initial and update copy operations” (page 8) .
Types of pair resynchronization
You can forward or reverse resynchronize pairs. A forward resynchronization resynchronizes from
the P-VOL to the S-VOL. A reverse resynchronization restores pairs by resynchronizing from the
S-VOL to the P-VOL.
Related topics
•
“Forward resynchronization” (page 52) .
•
“Reverse resynchronization” (page 53) .
Forward resynchronization
You can use one of the following methods to forward resynchronize pairs, including the requirements
and restrictions:
•
Normal Copy (Primary > Secondary). A full forward resynchronization from the P-VOL to the
S-VOL. During a Normal Copy, only the P-VOL is accessible to hosts for read/write operations.
•
Quick Resync (Primary > Secondary). A forward resynchronization from the P-VOL to the S-VOL
where data is not copied or resynchronized. The volumes are paired (“PAIR” status). The
update copy operation copies the differential data to the S-VOL.
During a Quick Resync, the P-VOL is accessible to hosts for read/write operations. Quick
Resync, even when a host I/O does not exist, does not ensure data consistency.
For more information about ensuring data consistency, see “Workflow for ensuring data
consistency” (page 47) .
52 Managing Business Copy pairs