Creating a cluster for PowerHA SystemMirror for Linux

You can configure the basic components of a cluster by using the options of the clmgr command.

The configuration path significantly automates the discovery and selection of configuration information and chooses default behaviors.

Prerequisite tasks for configuring the cluster

Before you configure a cluster, PowerHA® SystemMirror® for Linux must be installed on all nodes and connectivity must exist between the node where you are performing the configuration and all other nodes that need to be included in the cluster.

Network interfaces must be both physically and logically configured with the Linux operating system so that communication occurs from one node to each of the other nodes. The host name and IP address must be configured on each interface.
Note: All host name, service IP address, persistent IP address, and labels must be configured in the /etc/hosts file.

All node IP addresses must be added to the /etc/cluster/rhosts file before you configure the cluster to verify that information is collected from the systems that belong to the cluster. PowerHA SystemMirror uses all configured interfaces on the cluster nodes for cluster communication and monitoring. All configured interfaces are used to keep cluster IP addresses highly available.

Configuring a cluster

To configure a typical cluster component, complete the following steps:
Configure a cluster
To configure a cluster, use clmgr add cluster command.
Configure additional topology components
To configure additional components for a cluster, you can perform the following actions:
Configure the cluster resources
Configure the resources to be made highly available. For instructions, see Configuring resources for PowerHA SystemMirror for Linux to configure resources that must be shared among the nodes in the cluster. You can configure the following resources:
  • Application (scripts to start, stop, and monitor applications)
  • Service IP
  • Persistent IP
  • File system
Configure the resource groups
To create the resource groups for each set of related resources, use the clmgr add resource_group command. Additionally, you can add resources to a resource group when you create the resource group.
Assign resources to the respective resource group
To assign resources to each resource groups while creating a resource group, use the clmgr add resource_group command. To modify an existing resource group, use the clmgr modify resource_group command.
Manage and view log data
To adjust the log file view and log file management, use the clmgr modify log or clmgr view log command. This step is an optional step.
Display the cluster configuration
To view the cluster topology and resources configuration, use the clmgr query cluster or clmgr query resource_group command. This step is optional.
Configure disk heartbeat configuration
To configure disk heartbeat, use the clmgr add network command. This step is optional.
Perform additional configurations
The following optional cluster configuration steps can be performed depending on application requirements:
  • Configuring runtime policies of a resource group
  • Configuring dependencies between resource groups
  • Adding more applications
  • Configuring file collections
  • Configuring a cluster user or user group