Assigning mirrors to remote command devices

You assign the mirror IDs used by the configuration’s journals to the remote command devices. This enables UR control information regarding the delta resync to be transferred and then read at the secondary sites. This is necessary for the delta resync operation.

Prerequisites

• Required role: Storage Administrator (Remote Backup Management)

• To assign a mirror to a remote command device, the mirror’s status must be one of the following:

Initial, Active, Halt, Stopped, Hold, Holding, or Hold(Failure)

To use a mirror in Initial status, it must have mirror ID 0.

• A maximum of 16 mirrors can be shared with a remote command device.

• A maximum of 16 remote command devices can be used for the delta resync operation per storage system.

Procedure

1. Open the Remote Replication window.

In Command Suite:

1. On the Resources tab, expand the Storage Systems tree.

2. Right-click the target storage system, and click Remote Replication.

In Device Manager - Storage Navigator:

1. In the Explorer pane, expand the Storage Systems tree.

2. Expand the target storage system tree, expand Replication, and click Remote Replication.

2. Select the Mirrors tab, and then select a mirror (or multiple mirrors) to which you will assign the remote command device.

3. From the Actions menu, click Remote Replication > Assign Remote Command Devices.

4. In the Available Mirrors table, select the mirror.

At the primary site:

• Assign mirror ID 0 to the remote command device that is mapped to the TC secondary site.

• Assign the mirror ID used for the UR 3DC multi-target pair to the remote command device that is mapped to the secondary site.

At the TC secondary site:

• Assign mirror ID 0 to the remote command device that is mapped to the primary site.

• Assign the mirror ID used for the UR delta resync pair to the remote command device that is mapped to the UR secondary site.

At the UR secondary site:

• Assign the mirror ID used for the UR 3DC multi-target configuration to the remote command device that is mapped to the primary site.

• Assign the mirror ID used for the UR delta resync pair to the remote command device that is mapped to the TC secondary site.

5. In Remote Command Device, select the remote command device you want to assign.

6. Click Add. The mirror to which you assign the remote command device is added to the Selected Mirrors table. If you want to remove the added mirror from the Selected Mirrors table, select the mirror you want to delete, and then click Remove.

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.

10. To check newly assigned remote command devices, see the Journal Volumes window > Remote Command Device field.

• If a remote command device is assigned to the mirror, the LDEV number is displayed.

• If a remote command device is not assigned to the mirror, the field is blank.

• If a remote command device cannot be assigned to the mirror, a hyphen (-) is displayed.