HP XP P9500 User Manual page 33

NOTE: The P-VOL and S-VOL are synchronized only when the pair status changes from COPY(SP)
or PSUS(SP) to PSUS. Due to the Business Copy asynchronous update copy operations, this status
transition can take several minutes.
If you want the S-VOLs you are intending to split to be identical to the P-VOLs, stop all write
operations to the P-VOLs before splitting the pairs. This ensures that there are no updates to the
P-VOLs while the split operations are synchronizing the S-VOLs to the P-VOLs.
Triggers for change of pair status to PSUS
What happens to pairs in PSUS (SP) or COPY (SP) status depends on the system option mode 459
(ON or OFF; OFF is the default) and whether the S-VOL (or the pool volume associated with the
S-VOL) is an internal or external volume.
System option mode Type of S-VOL
459
OFF Internal volume
External volume
ON Internal volume
External volume
*
When S-VOL is the volume of Thin Provisioning, it is the volume in the pool that is associated with S-VOL.
*
When S-VOL is the volume of Thin Provisioning Z, this function cannot be performed.
Four options are available when splitting a pair:
Steady split, which is a typical pair split operation in which any remaining differential data
from the P-VOL is copied to the S-VOL and then the pair is split.
Quick split, in which the pair is immediately split so that the S-VOL is immediately available
for read and write I/O. Any remaining differential data is copied to the S-VOL in the
background.
At-Time Split, in which all pairs in a consistency group are split at the same time. Split time
indicates the time when you want to mirror P-VOL data in the S-VOLs. RAID Manager is
required.
Create and simultaneously split an L1 or L2 pair. This allows you to access S-VOLs as soon
as possible
Prerequisite Information
Pair status must be one of the following:
PAIR when splitting an existing pair
◦
◦ SMPL when creating and immediately splitting an L1 pair
◦ PSUS for the L1 pair, when creating and immediately splitting an L2 pair
When splitting an existing pair, the operation completes faster by stopping host access to the
P-VOL before the operation.
Procedure 1 To split a pair, or to create and split a pair
1. Click Actions > Local Copy > Business Copy/Snapshot > Pair Operation to open the Pair
Operation window.
*
What happens to pairs in PSUS (SP) or COPY (SP) status
All differential data is copied to cache in the storage system and then
the pair status changes to PSUS.
All differential data is copied to cache in the storage system, and then
de-staged to the external storage system. The pair status then changes
to PSUS.
Split and create pairs 33