The following steps will start all of the managed servers in a cluster.
Start the Administration server for the domain.
Start the Node Manager utility on all machines in the domain.
From the Administration console, right-click on the name of the cluster in the left panel.
Select the "Start this cluster ..." option from the drop-down menu.
The Administration console server will prompt you to confirm the command. Click "Yes."
Results of the start operation for each individual server can be viewed by clicking on the icon for that server in the left pane.