Red Hat Training

A Red Hat training course is available for Red Hat Enterprise Linux

2.5. Testing the Resource Configuration

In the cluster status display shown in Section 2.4, “Creating the Resources and Resource Groups with the pcs Command”, all of the resources are running on node z1.example.com. You can test whether the resource group fails over to node z2.example.com by using the following procedure to put the first node in standby mode, after which the node will no longer be able to host resources.
  1. The following command puts node z1.example.com in standby mode. 
    root@z1 ~]# pcs node standby z1.example.com
  2. After putting node z1 in standby mode, check the cluster status. Note that the resources should now all be running on z2. 
    [root@z1 ~]# pcs status
Cluster name: my_cluster
Last updated: Wed Jul 31 17:16:17 2013
Last change: Wed Jul 31 17:18:34 2013 via crm_attribute on z1.example.com
Stack: corosync
Current DC: z2.example.com (2) - partition with quorum
Version: 1.1.10-5.el7-9abe687
2 Nodes configured
6 Resources configured


Node z1.example.com (1): standby
Online: [ z2.example.com ]

Full list of resources:

 myapc	(stonith:fence_apc_snmp):	Started z1.example.com 
 Resource Group: apachegroup
     my_lvm	(ocf::heartbeat:LVM):	Started z2.example.com 
     my_fs	(ocf::heartbeat:Filesystem):	Started z2.example.com 
     VirtualIP	(ocf::heartbeat:IPaddr2):	Started z2.example.com 
     Website	(ocf::heartbeat:apache):	Started z2.example.com
    The web site at the defined IP address should still display, without interruption.
  3. To remove z1 from standby mode, enter the following command. 
    root@z1 ~]# pcs node unstandby z1.example.com

    Note

    Removing a node from standby mode does not in itself cause the resources to fail back over to that node. This will depend on the resource-stickiness value for the resources. For information on the resource-stickiness meta attribute, see Configuring a Resource to Prefer its Current Node in the Red Hat High Availability Add-On Reference.