Splitting the pairs in a mirror

A mirror normally has multiple pairs with the same master and restore journals groups. When you split a mirror, you split all of the pairs in the mirror. As with a normal pair split, data copying is suspended between the primary and secondary journals.

Prerequisites

• Pair status must be Active.

• A mirror can be split from the primary or secondary system.

Procedure

1. Open the Remote Replication window.

In Command Suite: On the Resources tab, expand the Storage Systems tree, right-click the target storage system, and click Remote Replication.

In Device Manager - Storage Navigator: In the Storage Systems tree, click Replication > Remote Replication.

2. Select the Mirrors tab, and then select the mirrors to be split.

3. From the Actions menu, click Remote Replication > Split Mirrors.

4. In the Split Mirrors window, review the mirrors that you selected in the Selected Mirrors table. To remove a mirror, select the it and click Cancel.

5. For Secondary Volume Write, specify whether data can be written to S-VOLs in the mirror while it is split.

• Enable: The host writes data to S-VOLs in the mirror. Available only when the selected mirror’s Attribute is Master. If Restore, Disable is used automatically.

• Disable: The host does not write data to S-VOLs in the mirror.

6. For Split Mode, specify whether data is written to S-VOLs in the mirror before the split operation runs.

• Flush: Copies all update data from to S-VOLs in the mirror before the split.

• Purge: Prevents update data from being copied to S-VOLs in the mirror before the split. Uncopied data is copied to the S-VOL when the pair is resynchronized.

7. Click Finish.

8. In the Confirm window, review the settings and enter a task name in the Task Name box.

9. Click Apply to save your settings to the system.