-# def clear_known_hosts (self):
-# utils.header("Messing with known_hosts for slice %s"%self.name())
-# hostnames=[]
-# # scan nodenames
-# for nodename in self.slice_spec['nodenames']:
-# (site_spec,node_spec) = self.test_plc.locate_node(nodename)
-# hostnames.append(node_spec['node_fields']['hostname'])
-# self.test_plc.run_in_guest("sed -i -e /^%s/d /root/.ssh/known_hosts"%node_spec['node_fields']['hostname'])
-# #scan public key and update the known_host file in the root image
-# self.test_plc.scan_publicKeys(hostnames)
-