【ironic】 booting from volume

hi:    The pike version of ironic support the feature: booting from volume. There is a question: when booting from volume, the baremetal node should be reachable to the storage node,but when deploy done, the baremetal's network  completely belong to the vpc. How could the baremetal node booting from volume??     I should add the extar storage nic to communicate with storage node??        expecting for the answer thanks guo