Initial Copy; Update Copy - HP StorageWorks P9000 - Disk Arrays User Manual

Initial copy

When you create a pair, the initial copy is started by the system, and all the data in the S-VOL is
copied to the T-VOL.
Before the pair creation the pair's status is Simplex.
While the initial copy is in progress, the status is Pending.
The status changes to Duplex when the initial copy is complete.
Figure 2 Initial copy operation
An S-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 S-VOL in Duplex status is marked as differential data and stored in bitmaps for
transfer to the T-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 Z overview