10.6. Adding New Resource Groups or Resources in an Active Cluster

The following procedure describes how to add a resource group and resources to an active cluster. To add resources to an existing resource group, perform resource configuration (Step 4), resource diagnostics (Step 5) and add resources to the resource group (Step 6).

1. Identify all the resources that have to be moved together. These resources running on a node should be able to provide a service to the client. These resources should be placed in a resource group. For example, Netscape webserver mfg-web, its IP address 192.26.50.40, and the filesystem /shared/mfg-web containing the web configuration and document pages should be placed in the same resource group (for example, mfg-web-rg).

2. Configure the resources in all nodes in the cluster where the resource group is expected to be online. For example, this might involve configuring netscape web server mfg-web on nodes web-node1 and web-node2 in the cluster.

3. Create a failover policy. Determine the type of failover attribute required for the resource group. The cluster_mgr template (/usr/lib/failsafe/cmgr-templates/cmgr-create-failover_policy) can be used to create the failover policy.

4. Configure the resources in configuration database. There are cluster_mgr templates to create resources of various resource types in /usr/lib/failsafe/cmgr-templates directory. For example, the volume resource, the /shared/mfg-web filesystem, the 192.26.50.40 IP_address resource, and the mfg-web Netscape_web resource have to be created in the configuration database. Create the resource dependencies for these resources.

5. Run resource diagnostics. For information on the diagnostic commands, see Chapter 8.

6. Create resource group and add resources to the resource group. The cluster_mgr template (/usr/lib/failsafe/cmgr-templates/cmgr-create-resource_group) can be used to create resource group and add resources to resource group.

   All resources that are dependent on each other should be added to the resource group at the same time. If resources are added to an existing resource group that is online in a node in the cluster, the resources are also made online on the same node.