HP XP Racks - Manual (Page 9)

NOTE: Data consistency is not ensured for BC pairs in “PAIR” status.
For more information about ensuring data consistency, see “Workflow for ensuring data
consistency” (page 47) .
The following image shows the initial copy operation.
A P-VOL continues receiving updates from the host during the initial copy.
Related topics
•
“BC pair creation” (page 34) .
Update copy workflow
Update copy is an operation that is performed by XP7 to asynchronously copy new data, differential
data, on the P-VOL of a copy volume to the S-VOL.
XP7 goes through the following process to create an update copy:
1. XP7 marks I/O to the P-VOL in “PAIR” status as differential data and stores the data in bitmaps
for transfer to the S-VOL.
2. A write I/Os to the P-VOL starts. XP7 starts the update copy operation.
NOTE: The timing of the update copy operation is based on the amount of differential data
that accumulates and the elapsed time since the previous update.
The following image shows the update copy operation.
Initial and update copy operations 9