Initial Copy; Update Copy - HP XP P9500 User Manual

Initial copy

When you create a pair, the initial copy is started by the system, and all the data in the P-VOL is
copied to the S-VOL.
Before the pair creation the pair's status is SMPL.
While the initial copy is in progress, the status is COPY.
The status changes to PAIR when the initial copy is complete.
Figure 3 Initial copy operation
A P-VOL continues receiving updates from the host during the initial copy. When the initial copy
is completed, update copy operations start.

Update copy

I/O sent to the P-VOL in PAIR status is marked as differential data and stored in bitmaps for transfer
to the S-VOL. Update copy operations are performed periodically by the system. 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.
8 Business Copy overview