9.11 Cluster Migrating Resources to Different Nodes

You can migrate cluster resources to different servers in your cluster without waiting for a failure to occur. You might want to migrate resources to lessen the load on a specific server, to free up a server so it can be brought down for scheduled maintenance, or to increase the performance of the resource or application by putting it on a faster machine. The node you choose must be in the resource’s preferred nodes list and available to run the resource.

Migrating resources lets you balance the load and evenly distribute applications among the servers in your cluster.

Using iManager

  1. In iManager, select Clusters > My Clusters.

  2. Select the cluster that you want to manage.

    If the cluster does not appear in your list, add the cluster to your list as described in Section 8.2, Setting Up a Personalized List of Clusters to Manage.

  3. On the Cluster Manager page, select the check box next to the resource you want to cluster migrate, then click Migrate.

    A page appears, displaying a list of possible servers that you can migrate this resource to.

  4. Select a server from the list to migrate the resource to, then click OK to migrate the resource to the selected server.

Using Console Commands

  1. As the root user, enter the following at the command prompt of a cluster node:

    cluster migrate <resource_name> {<node_name> | -list | -most | -next}
    

    Migrates the specified resource from the node where it is currently running to the node you specify in the command. The node you migrate the resource to must be running in the cluster and also be in the resource’s Preferred Nodes list.

    Options

    <node_name>

    Migrates the resource to the specified node if possible. No action is taken if the specified node is not in the resource’s preferred nodes list, there is a Resource Mutual Exclusion conflict on the specified node, or the specified node is not currently active in the cluster.

    -l , -list

    Shows the preferred nodes list for the specified resource.

    -m , -most

    Migrates the specified resource to the most preferred node currently in the cluster. If the resource is running on such a node, no action is taken.

    -n , -next

    Migrates the resource to the node in the preferred node list that is next in order to the node where the resource is currently running. If there is no next node or all such nodes are not in the cluster currently, it searches from the beginning of the resource’s preferred nodes list. No action is taken if a new destination could not be determined after the search is exhausted.

    Examples

    Move res1 from the current node to node2 in the resource’s preferred nodes list. The resource is migrated only if there are no Resource Mutual Exclusion conflicts on the target node.

    cluster migrate res1 node2
    

    List the preferred nodes for resource AUTO_POOL_14_SERVER.

    cluster migrate AUTO_POOL_14_SERVER -l
     
    Preferred nodes for resource ‘AUTO_POOL_14_SERVER’
      CG-06
      CG-05
      CG-04
      CG-03
      CG-02
      CG-01
      CG-08
      CG-07
     
    Status for Resource: AUTO_POOL_14_SERVER
    Running on CG-05  Lives: 65
    Revision: 5