HP XP7 Storage - Manual (Page 69)

track of which pairs have the DFW required setting, and make sure that DFW to the
S-VOL is not blocked.
If a Cnt Ac-S Z pair is established using PPRC commands, the DFW to S-VOL option is
set to the DFW not required setting.
7. For Host I/O Time Stamp Transfer, specify whether the host I/O time stamp is transferred
from P-VOL to S-VOL. Enable transfers, Disable does not transfer; Disable is the default.
9. Back again in the Primary Volume Selection box, select the primary volume to be copied first
and click Add>. The volume and pair information moves to the Selected Pairs table.
In the Selected Pairs table, you can change pair options by selecting it and clicking Change
Settings. Remove a pair by selecting it and clicking Remove.
10. Click Finish.
11. In the Confirm window, review the settings and enter a task name in the Task Name box.
12. Click Apply to save your settings in the system.
Splitting pairs
You can split a pair, which suspends data copying to the S-VOL.
When a pair is split:
•
I/O writes from the host continue to the P-VOL, but stop to the S-VOL.
•
Any current update copy operation completes to the S-VOL, ensuring data consistency to the
point of the split operation.
•
Pair status changes to Suspended.
•
The primary system records the updated tracks to the P-VOL that occur after the split as
differential data. This data is copied to the S-VOL when the pair is resynchronized.
•
You can set an option to block updates to the P-VOL while the pair is split. This results in the
P-VOL and S-VOL staying synchronized.
•
Another option is to enable system write to the S-VOL from a host. The secondary system
records the updated tracks as differential bitmaps. When the pair is resynchronized, the
secondary system sends the differential bitmaps to the primary system, which merges all
differential bitmaps to determine which tracks are out-of-sync.
Prerequisite information
•
Pair status must be Pending or Duplex.
Procedure 12 To split one or more pairs
1. In the Storage Systems tree, click Replications > Remote Replications.
2. In the Remote Replications window, click the Cnt Ac-S Pairs tab, then select the pair to be split.
3. From the Actions menu, click Remote Replications > Split Pairs.
4. In the Split Pairs window, ensure that the pair to be split appears in the Selected Pairs table.
Splitting pairs 69