3.2.4. Standby Mode

The following command puts the specified node into standby mode. The specified node is no longer able to host resources. Any resources currently active on the node will be moved to another node. If you specify the --all, this command puts all nodes into standby mode.
You can use this command when updating a resource's packages. You can also use this command when testing a configuration, to simulate recovery without actually shutting down a node.
pcs cluster standby node | --all
The following command removes the specified node from standby mode. After running this command, the specified node is then able to host resources. If you specify the --all, this command removes all nodes from standby mode.
pcs cluster unstandby node | --all
Note that when you execute the pcs cluster standby command, this adds constraints to the resources to prevent them from running on the indicated node. When you execute the pcs cluster unstandby command, this removes the constraints. This does not necessarily move the resources back to the indicated node; where the resources can run at that point depends on how you have configured your resources initially. For information on resource constraints, see Chapter 6, Resource Constraints.