diff --git a/wally/sensors.py b/wally/sensors.py
index c86aeb4..4f00a3e 100644
--- a/wally/sensors.py
+++ b/wally/sensors.py
@@ -1,25 +1,34 @@
-from typing import List, Dict, Tuple, Any
+import array
+import logging
+from typing import List, Dict, Tuple
 
+from . import utils
 from .test_run_class import TestRun
 from . import sensors_rpc_plugin
 from .stage import Stage, StepOrder
 
 plugin_fname = sensors_rpc_plugin.__file__.rsplit(".", 1)[0] + ".py"
-SENSORS_PLUGIN_CODE = open(plugin_fname).read()
+SENSORS_PLUGIN_CODE = open(plugin_fname, "rb").read()
 
 
-# TODO(koder): in case if node has more than one role sensor settigns might be incorrect
+logger = logging.getLogger("wally")
 
+
+# TODO(koder): in case if node has more than one role sensor settings might be incorrect
 class StartSensorsStage(Stage):
     priority = StepOrder.START_SENSORS
     config_block = 'sensors'
 
     def run(self, ctx: TestRun) -> None:
-        if 'sensors' not in ctx.config:
-            return
+        if  array.array('L').itemsize != 8:
+            message = "Python array.array('L') items should be 8 bytes in size, not {}." + \
+                " Can't provide sensors on this platform. Disable sensors in config and retry"
+            logger.critical(message.format(array.array('L').itemsize))
+            raise utils.StopTestError()
 
         per_role_config = {}  # type: Dict[str, Dict[str, str]]
-        for name, val in ctx.config['sensors'].copy():
+
+        for name, val in ctx.config.sensors.roles_mapping.raw().items():
             if isinstance(val, str):
                 val = {vl.strip(): ".*" for vl in val.split(",")}
             elif isinstance(val, list):
@@ -39,14 +48,47 @@
                 per_role_config[name] = new_vals
 
         for node in ctx.nodes:
-            node_cfg = {}  # type: Dict[str, str]
+            node_cfg = {}  # type: Dict[str, Dict[str, str]]
             for role in node.info.roles:
                 node_cfg.update(per_role_config.get(role, {}))
 
+            nid = node.info.node_id()
             if node_cfg:
-                node.conn.upload_plugin(SENSORS_PLUGIN_CODE)
-                ctx.sensors_run_on.add(node.info.node_id())
-            node.conn.sensors.start()
+                # ceph requires additional settings
+                if 'ceph' in node_cfg:
+                    node_cfg['ceph'].update(node.info.params['ceph'])
+                    node_cfg['ceph']['osds'] = [osd.id for osd in node.info.params['ceph-osds']]
+
+                logger.debug("Setting up sensort RPC plugin for node %s", nid)
+                node.upload_plugin("sensors", SENSORS_PLUGIN_CODE)
+                ctx.sensors_run_on.add(nid)
+                logger.debug("Start monitoring node %s", nid)
+                node.conn.sensors.start(node_cfg)
+            else:
+                logger.debug("Skip monitoring node %s, as no sensors selected", nid)
+
+
+def collect_sensors_data(ctx: TestRun, stop: bool = False):
+    for node in ctx.nodes:
+        node_id = node.info.node_id()
+        if node_id in ctx.sensors_run_on:
+
+            if stop:
+                func = node.conn.sensors.stop
+            else:
+                func = node.conn.sensors.get_updates
+
+            data, collected_at_b = func()  # type: Dict[Tuple[bytes, bytes], List[int]], List[float]
+
+            collected_at = array.array('f')
+            collected_at.frombytes(collected_at_b)
+
+            mstore = ctx.storage.sub_storage("metric", node_id)
+            for (source_name, sensor_name), values_b in data.items():
+                values = array.array('Q')
+                values.frombytes(values_b)
+                mstore.append(values, source_name, sensor_name.decode("utf8"))
+                mstore.append(collected_at, "collected_at")
 
 
 class CollectSensorsStage(Stage):
@@ -54,16 +96,7 @@
     config_block = 'sensors'
 
     def run(self, ctx: TestRun) -> None:
-        for node in ctx.nodes:
-            node_id = node.info.node_id()
-            if node_id in ctx.sensors_run_on:
-
-                data, collected_at = node.conn.sensors.stop()  # type: Dict[Tuple[str, str], List[int]], List[float]
-
-                mstore = ctx.storage.sub_storage("metric", node_id)
-                for (source_name, sensor_name), values in data.items():
-                    mstore[source_name, sensor_name] = values
-                    mstore["collected_at"] = collected_at
+        collect_sensors_data(ctx, True)
 
 
 # def delta(func, only_upd=True):