Adding a node to a device domain
A device domain is a subset of nodes in a cluster that shares device resources.
If you are implementing a high-availability solution that contains independent disk pools-based technologies, such as switched disk or cross-site mirroring, you must define the node as a member of a device domain. After you add the node to a device domain, you can create a device cluster resource group (CRG) that defines the recovery domain for the cluster. All nodes that will be in the recovery domain for a device CRG must be in the same device domain. A cluster node can belong to only one device domain.
To create and manage device domains, you must have 
PowerHA®
Option 41 (HA Switchable Resources) installed. A valid license key must exist on all cluster nodes in the device domain.
The PowerHA graphical interface simplifies device domain management by ensuring that the required nodes are in a device domain when a device CRG is created or when a node is added to a device CRG.
To add a node to a device domain using the PowerHA graphical interface, follow these steps:
- In a Web browser, enter http://mysystem:2001, where mysystem is the host name of the system.
- Log on to the system with your user profile and password.
- Click PowerHA from
the IBM® Navigator
for i window.
- On the PowerHA page, click Cluster Nodes.
- On the Cluster Nodes page, select Properties ... from the context menu of the node you want to add to a device domain.
- Click Edit in the General section of the Properties page.
- Specify the name of the device domain to which you want to add the node in the Device Domain field and click Save.