HP XP7 Storage - Manual (Page 14)

resynchronized, the primary system merges the P-VOL and S-VOL bitmaps, and the differential data
is copied to the S-VOL.
The number of bitmap areas affects the maximum possible number of pairs that can be created in
the system.
S-VOL write option
When splitting a pair, you can set an option allowing write I/O to the S-VOL. When you
resynchronize a split pair whose S-VOL is write-enabled, the secondary system sends the S-VOL
track bitmap to the primary system, which merges the P-VOL and S-VOL bitmaps to determine which
tracks are out of sync. This ensures proper resynchronization of the pair.
Pair status
Every pair operation results in a change in pair status. Also, when you want to perform an operation,
the pair must have a specific status in order to for the operation to run.
You will monitor pair status to ensure that you can perform the desired operation, and to ensure
that an operation completed successfully.
To become familiar with the operations that result in the pair statuses, it is recommended that you
review
“Pair status definitions” (page 62) .
14 Continuous Access Journal overview