3.13 How to create a cluster resource?

Cluster resources should be created for every shared file system or any server-based applications or services you want to make available to users at all times.

Select a cluster, then select Dashboard.
Navigate to the Resources tab and click Create resource.

Alternatively, you can access this option from the dashboard by clicking Actions > Create resource.

NOTE:A pool resource is automatically created when an NSS pool is created.

A wizard is displayed to create a new resource.

Configuration

Specify the name of the resource you want to create.

In Type, select one of the available templates. The cluster resource templates can be used on physical servers, virtualization host servers, and virtual machine (VM) guest servers.

Cluster Resource Template	Use
Generic	An empty template.
Generic_IP_Service	This template is auto-populated with commands or variables and is used to create cluster resources for a certain server applications that run on your cluster.
Generic_FS	This template is auto-populated with commands or variables and is used to configure resource for Linux Logical Volume Manager (LVM).
DNS	This template is auto-populated with commands or variables and is used to configure resource for the DNS service.
DHCP	This template is auto-populated with commands or variables and used to configure resource for the DHCP service.

If you want the resource to be immediately available after creation, enable Initialize after creation.
Click Next.

Policies
1. If you want to ensure that the resource runs only on the master node in the cluster, select Resource follows master.
  
  If the master node in the cluster fails, the resource fails over to whichever node becomes the master.
2. If you don’t want the cluster-wide timeout period and node number limit enforced, select Ignore quorum.
  
  This ensures that the resource is launched immediately on any server in the Preferred Nodes list as soon as any server in the list is brought online.
3. Specify the Failover mode. When the mode is enabled, the resource automatically starts on the next server in the Preferred Nodes list if there is a hardware or software failure. If the mode is disabled, you can intervene after a failure occurs and before the resource is moved to another node.
4. Specify the Start mode. When the mode is enabled, the resource automatically starts on a server when the cluster is first brought up. If the mode is disabled, you can manually start the resource on a server when you want, instead of having it automatically start when servers in the cluster are brought up.
5. Specify the Failback mode. When the mode is set to Disabled, the resource does not fall back to its most preferred node when the most preferred node rejoins the cluster. If the mode is set to Auto, the resource automatically falls back to its most preferred node when the most preferred node rejoins the cluster. Set the mode to Manual to prevent the resource from moving back to its preferred node when that node is brought back online, until you are ready to allow it to happen.
6. Click Next.
Assigned nodes: Allows you to assign nodes to use for the resource. You also sequence the list of nodes to specify the preferred order that the nodes will be tried when a resource is brought online after its current node fails.
1. In the Unassigned area, select a node that the resource can use, and then click the arrow button to move the selected node to the Assigned nodes area.
  
  Repeat this step for all of the cluster nodes you want to assign to the resource.
2. In the Assigned area, select a node that you want to unassign from the resource, then click the arrow button to move the selected node to the Unassigned nodes area.
3. Click Next.
Scripts: You can add an unload script to specify how the application or resource should terminate. Resource monitoring allows cluster to detect a the resource failure independently of its ability to detect node failures.
1. A load script is required for each resource, service, disk, or pool in your cluster. The load script specifies the commands to start the resource or service on a server.
  1. Edit or add the necessary commands to the script to load the resource on a server.
  2. Specify the Timeout value. The timeout value determines how much time the script is given to complete. If the script does not complete within the specified time, the resource becomes comatose. The timeout value is applied only when the resource is migrated to another node. It is not used during resource online/offline procedures.
2. An unload script is not required by all resources, but is required for cluster-enabled Linux partitions. You can add an unload script to specify how the application or resource should terminate. Programs should be unloaded in the reverse order of how they were loaded. This ensures that supporting programs are not unloaded before programs that rely on them in order to function properly.
  1. Edit or add the necessary commands to the script to unload the resource on a server.
  2. Specify the Timeout value. The timeout value determines how much time the script is given to complete. If the script does not complete within the specified time, the resource becomes comatose. The timeout value is applied only when the resource is migrated to another node. It is not used during resource online/offline procedures.
3. The monitor script is used to monitor the status of service or storage objects.
  1. Edit or add the necessary commands to the script to monitor the resource on the server.
  2. Specify the Timeout value. The timeout value determines how much time the script is given to complete. If the script does not complete within the specified time, the failure action you have chosen gets initiated.
4. Click Next.
Monitoring: Allows you to monitor the health of the specified resource by using a script that you create or customize. By default, resource monitoring is disabled. To enable or modify the settings, you must configure the resource.
Summary: Displays a summary of the resource. Review it and click Finish.