Forcibly deleting GAD pairs (for paired volumes)

Use the following procedure to forcibly delete a global-active device pair. When you forcibly delete a pair, you must delete the pair from both the primary and secondary storage systems, so you need to perform this procedure twice, once for each volume.

 If the server can access both pair volumes after the pair is deleted, a data failure might occur because the contents of the volumes are no longer consistent after the pair deletion. To ensure data consistency and avoid a possible data failure, delete the pair according to the following procedure.

1. Stop access from the server to one of the pair volumes.

2. Use the procedure below to forcibly delete the pair specifying the volume to which you stopped server access, and specify Disable for Volume Access.

The virtual LDEV ID is deleted from the volume, and the reserve attribute is set for the volume. When the reserve attribute is set, the server cannot access the volume.

3. Use the procedure below to forcibly delete the pair specifying the volume to which server access continues, and specify Enable for Volume Access.

• When a global-active device pair is deleted from the secondary storage system, the primary and secondary volumes have the same volume label. Be careful not to generate system problems due to duplicate volumes.

• You can forcibly delete a pair only when the I/O mode of both the primary and secondary volumes is Block. If you want to forcibly delete a pair when the I/O mode is not Block, call customer support.

• If you need to forcibly delete a GAD pair in a GAD+UR configuration, first delete the UR pair and the UR delta resync pair, and then delete the GAD pair forcibly.

Prerequisite information

• Storage Administrator (Provisioning) role is required.

• In the Remote Replication window or the View Pair Properties window, the pair status and I/O mode must satisfy one of the following conditions:

• The pair status is PSUS and the I/O mode is Local.

• The pair status is PSUE and the I/O mode is Local.

• The pair status is SSWS.

Procedure

1. In the Storage Systems tree, select Replication, and the Remote Replication.

2. In the GAD Pairs tab, select the pair you want to delete, and display the Delete Pairs window in one of the following methods:

• In More Actions, click Delete Pairs.

• From the Actions menu, select Remote Replication, and then Delete Pairs.

3. Check that the pair you want to delete is displayed in the Selected Pairs table.

4. Select Force in Delete Mode.

5. In Volume Access, select whether to permit access from the server after the pair is deleted.

Select Enable to keep the virtual LDEV ID of the volume in the local storage system and permit access from the server. Select Disable to delete the virtual LDEV ID of the volume in the local storage system and deny access from the server.

 See the caution above about data failure due to server access to both pair volumes after pair deletion.

6. Click Finish.

7. In the Confirm window, check the settings you made, and then enter the task name in Task Name.

8. Click Apply.

The task is registered, and if the Go to tasks window for status check box is selected, the Tasks window appears.

After deleting a pair, in the Remote Replication window, check that the GAD pair is not displayed.

To check the status of a pair that is being deleted, click the Refresh button at the top right corner of the main window of Device Manager - Storage Navigator, or display detailed information in the View Pair Properties window.