How can I add child resources to my cluster.conf with ccs in RHEL 6?

Issue

• I need to add a child resource to an existing resource in my cluster.conf using the ccs command.

<service name="service_example" recovery="restart">          
        <script ref="script_resource">           
               <fs ref="fs_resource">  
                       <ip ref="192.168.100.1"/>   
               </fs> 
        </script>                     
</service>  

• When I try to add a child resource to an existing resource in my cluster.conf using the ccs command I get the following error:

# ccs -h localhost --addsubservice ip2 ip_resource:ip ref=192.168.100.1              
Unable to find service ip[2]