Hitachi MP-96RD625-01 manual Hitachi Universal Replicator for IBM /OS User’s Guide

Configuring Paths and Ports to Establish Connections among Secondary

Storage Systems

To establish connections among secondary storage systems, you must configure external ports on the storage system that should be used as the supervisor DKC. After that, you must configure paths between these external ports and the target ports on the storage systems that should be used as subordinate DKCs. In the example in Figure 3-7, the secondary storage system 1 has external ports, each of which is connected with a target port on the secondary storage system 2 and 3. For details on external ports, please refer to the Universal Volume Manager User's Guide. For details on configuring paths, please refer to the LUN Manager User's Guide.

By using fibre channel switches, target ports can also be connected to RCU target ports on secondary storage systems. For details on RCU target ports, see section Initiator Ports and RCU Target Ports. For details on configuring ports, see section Configuring Port Attributes.

Creating Remote Command Devices to Establish Connections among

Secondary Storage Systems

To establish connections among secondary storage systems, first you must create a command device in each of the secondary storage systems. Next you must create mapping between command devices in the supervisor DKC and the subordinate DKCs. Thus, the supervisor DKC will be able to use command devices in subordinate DKCs via remote command devices.

In the example of Figure 3-7, the command devices A and B are created in the secondary storage systems 2 and 3. Also, remote command devices are created in the secondary storage system 1 (i.e., the supervisor DKC), and are mapped to the secondary storage systems 2 and 3 (i.e., subordinate DKCs).

The emulation type of command devices and remote command devices must be OPEN-V. For details on remote command devices, please refer to the Universal Volume Manager User's Guide.

Caution: If maintenance operations are performed on remote command devices (for example, the devices A' and B' in Figure 3-7) that are used for connections among secondary storage systems, the pair will be suspended according to a failure. To avoid this, you must remove all journal groups in the extended consistency group that uses the remote command devices to be maintained.

3-22 Chapter 3 Preparing for Universal Replicator z/OS Operations

Hitachi Universal Replicator for IBM /OS User’s Guide