diff --git a/cluster-mgmt/conf/onos-cluster.conf b/cluster-mgmt/conf/onos-cluster.conf
index d36dd35..ddf99b2 100644
--- a/cluster-mgmt/conf/onos-cluster.conf
+++ b/cluster-mgmt/conf/onos-cluster.conf
@@ -10,6 +10,10 @@
 # Protocol used by RAMCloud cluster (fast+udp by default)
 #cluster.hosts.ramcloud.protocol = fast+udp
 
+# Number of RAMCloud replicas (0 by default)
+# On N node cluster, maximum value will be N-1 replicas
+#cluster.hosts.ramcloud.server.replicas = 0
+
 # Communication method used for Hazelcast communication
 #cluster.hosts.hazelcast.network = multicast
 cluster.hosts.hazelcast.network = tcp-ip
diff --git a/cluster-mgmt/conf/template/onos_node.conf.template b/cluster-mgmt/conf/template/onos_node.conf.template
index b6e069d..0dadf66 100644
--- a/cluster-mgmt/conf/template/onos_node.conf.template
+++ b/cluster-mgmt/conf/template/onos_node.conf.template
@@ -32,6 +32,11 @@
 # Port number of RAMCloud server (12242 by default)
 ramcloud.server.port = __RAMCLOUD_SERVER_PORT__
 
+# RAMCloud server option replicas (0 by default)
+# This value must be the same cluster wide.
+# On N node cluster, maximum value will be N-1 replicas
+ramcloud.server.replicas = __RAMCLOUD_SERVER_REPLICAS__
+
 # List of hostname/ip[:port] which forms Hazelcast datagrid
 # If this value is empty, Hazelcast will be set to multicast mode.
 # Inversely, if this value is set, multicast settings will be ignored.
diff --git a/cluster-mgmt/onos-cluster.sh b/cluster-mgmt/onos-cluster.sh
index 0e03c29..fac7110 100755
--- a/cluster-mgmt/onos-cluster.sh
+++ b/cluster-mgmt/onos-cluster.sh
@@ -31,12 +31,13 @@
   echo "${CLUSTER_CONF} not found."
   exit 1
 fi
-CLUSTER_HOSTS=$(read-conf ${CLUSTER_CONF}       cluster.hosts.names             `hostname` | tr ',' ' ')
-CLUSTER_BACKEND=$(read-conf ${CLUSTER_CONF}     cluster.hosts.backend)
-CLUSTER_RC_PROTOCOL=$(read-conf ${CLUSTER_CONF} cluster.hosts.ramcloud.protocol "fast+udp")
-CLUSTER_HC_NETWORK=$(read-conf ${CLUSTER_CONF}  cluster.hosts.hazelcast.network)
-CLUSTER_HC_ADDR=$(read-conf ${CLUSTER_CONF}     cluster.hosts.hazelcast.multicast.address "224.2.2.3")
-CLUSTER_HC_PORT=$(read-conf ${CLUSTER_CONF}     cluster.hosts.hazelcast.multicast.port    "54327")
+CLUSTER_HOSTS=$(read-conf ${CLUSTER_CONF}              cluster.hosts.names                       `hostname` | tr ',' ' ')
+CLUSTER_BACKEND=$(read-conf ${CLUSTER_CONF}            cluster.hosts.backend)
+CLUSTER_RC_PROTOCOL=$(read-conf ${CLUSTER_CONF}        cluster.hosts.ramcloud.protocol           "fast+udp")
+CLUSTER_RC_SERVER_REPLICAS=$(read-conf ${CLUSTER_CONF} cluster.hosts.ramcloud.server.replicas    "0")
+CLUSTER_HC_NETWORK=$(read-conf ${CLUSTER_CONF}         cluster.hosts.hazelcast.network)
+CLUSTER_HC_ADDR=$(read-conf ${CLUSTER_CONF}            cluster.hosts.hazelcast.multicast.address "224.2.2.3")
+CLUSTER_HC_PORT=$(read-conf ${CLUSTER_CONF}            cluster.hosts.hazelcast.multicast.port    "54327")
 ############################################
 
 
@@ -192,6 +193,7 @@
   sed -i -e "s|__RAMCLOUD_IP__|${rc_ip}|" ${tempfile}
   sed -i -e "s|__RAMCLOUD_COORD_PORT__|${rc_coord_port}|" ${tempfile}
   sed -i -e "s|__RAMCLOUD_SERVER_PORT__|${rc_server_port}|" ${tempfile}
+  sed -i -e "s|__RAMCLOUD_SERVER_REPLICAS__|${CLUSTER_RC_SV_REPLICAS}|" ${tempfile}
   
   if [ ${CLUSTER_HC_NETWORK} = "tcp-ip" ]; then
     sed -i -e "s|__HAZELCAST_MEMBERS__|${hc_hosts}|" ${tempfile}
diff --git a/conf/onos_node.conf b/conf/onos_node.conf
index 75f9aa0..8215ce4 100644
--- a/conf/onos_node.conf
+++ b/conf/onos_node.conf
@@ -25,7 +25,7 @@
 # Protocol used by RAMCloud coordinator (fast+udp by default)
 #ramcloud.coordinator.protocol = fast+udp
 
-# IP address of RAMCloud coordinator (host.ip by default)
+# Listening address of RAMCloud coordinator (host.ip or 0.0.0.0 by default)
 #ramcloud.coordinator.ip = 127.0.0.1
 
 # Port number of RAMCloud coordinator (12246 by default)
@@ -38,7 +38,7 @@
 # Protocol used by RAMCloud server (fast+udp by default)
 #ramcloud.server.protocol = fast+udp
 
-# IP address of RAMCloud server (host.ip by default)
+# Listening address of RAMCloud server (host.ip or 0.0.0.0 by default)
 #ramcloud.server.ip = 127.0.0.1
 
 # Port number of RAMCloud server (12242 by default)
diff --git a/onos.sh b/onos.sh
index 045289b..b155176 100755
--- a/onos.sh
+++ b/onos.sh
@@ -162,7 +162,9 @@
  \$ ${scriptname} status
     Show status of ONOS-related processes
  \$ ${scriptname} {zk|rc-coord|rc-server|core} {start|stop|restart|status}
-    Control specific ONOS-related process"
+    Control specific ONOS-related process
+ \$ ${scriptname} rc deldb
+    Delete data in RAMCloud"
   
   echo "${usage}"
 }
@@ -503,11 +505,21 @@
 
 ### Functions related to RAMCloud coordinator
 function rc-coord-addr {
-  echo "${RC_COORD_PROTOCOL}:host=${RC_COORD_IP},port=${RC_COORD_PORT}"
+  local host=${RC_COORD_IP}
+  if [ -z "${host}" ]; then
+    # falling back to 0.0.0.0
+    host="0.0.0.0"
+  fi
+  echo "${RC_COORD_PROTOCOL}:host=${host},port=${RC_COORD_PORT}"
 }
 
 function rc-server-addr {
-  echo "${RC_SERVER_PROTOCOL}:host=${RC_SERVER_IP},port=${RC_SERVER_PORT}"
+  local host=${RC_SERVER_IP}
+  if [ -z "${host}" ]; then
+    # falling back to 0.0.0.0
+    host="0.0.0.0"
+  fi
+  echo "${RC_SERVER_PROTOCOL}:host=${host},port=${RC_SERVER_PORT}"
 }
 
 function rc-coord {
@@ -708,7 +720,18 @@
 }
 
 function del-server-backup {
-  # TODO might want confirmation, since data can be lost
+  echo -n "Delete RAMCloud backup server data [y/N]? "
+  while [ 1 ]; do
+    read key
+    if [ "${key}" == "Y" -o "${key}" == "y" ]; then
+      break
+    elif [ -z "${key}" -o "${key}" == "N" -o "${key}" == "n" ]; then
+      echo "Cancelled."
+      return
+    fi
+    echo "[y/N]? "
+  done
+
   echo -n "Removing RAMCloud backup server data ... "
   local rc_datafile=$(read-conf ${ONOS_CONF} ramcloud.server.file "/var/tmp/ramclouddata/backup.${ONOS_HOST_NAME}.log")
   rm -f ${rc_datafile}
@@ -935,6 +958,7 @@
     rc-server $2
     ;;
   rc)
+    # TODO make deldb command more organized (clarify when it can work)
     rc-coord $2
     rc-server $2
     ;;