diff --git a/ceilometer/compute/instance.py b/ceilometer/compute/instance.py
index dff5ec6e0..7b312ef6d 100644
--- a/ceilometer/compute/instance.py
+++ b/ceilometer/compute/instance.py
@@ -17,6 +17,19 @@
 # under the License.
 """Common code for working with instances
 """
+from oslo.config import cfg
+
+OPTS = [
+    cfg.ListOpt('reserved_metadata_namespace',
+                default=['metering.'],
+                help='list of metadata prefixes resevred for metering use',
+                ),
+    cfg.IntOpt('reserved_metadata_length',
+               default=256,
+               help='limit on length of reserved metadata values'),
+]
+
+cfg.CONF.register_opts(OPTS)
 
 INSTANCE_PROPERTIES = [
     # Identity properties
@@ -36,6 +49,24 @@ INSTANCE_PROPERTIES = [
     'vcpus']
 
 
+def add_reserved_user_metadata(instance, metadata):
+    limit = cfg.CONF.reserved_metadata_length
+    user_metadata = {}
+    for prefix in cfg.CONF.reserved_metadata_namespace:
+        md = dict(
+            (k[len(prefix):].replace('.', '_'),
+             v[:limit] if isinstance(v, basestring) else v)
+            for k, v in instance.metadata.items()
+            if (k.startswith(prefix) and
+                k[len(prefix):].replace('.', '_') not in metadata)
+        )
+        user_metadata.update(md)
+    if user_metadata:
+        metadata['user_metadata'] = user_metadata
+
+    return metadata
+
+
 def get_metadata_from_object(instance):
     """Return a metadata dictionary for the instance.
     """
@@ -57,4 +88,5 @@ def get_metadata_from_object(instance):
 
     for name in INSTANCE_PROPERTIES:
         metadata[name] = getattr(instance, name, u'')
-    return metadata
+
+    return add_reserved_user_metadata(instance, metadata)
diff --git a/tests/compute/test_instance.py b/tests/compute/test_instance.py
index e5bb06148..092213840 100644
--- a/tests/compute/test_instance.py
+++ b/tests/compute/test_instance.py
@@ -67,7 +67,10 @@ class TestLocationMetadata(base.TestCase):
                                               'links': [{"rel": "bookmark",
                                                          'href': 2}]},
                                     'flavor': {'id': 1},
-                                    'hostId': '1234-5678'}
+                                    'hostId': '1234-5678',
+                                    'metadata': {'metering.autoscale.group':
+                                                 'X' * 512,
+                                                 'metering.ephemeral_gb': 42}}
 
         self.instance = FauxInstance(**self.INSTANCE_PROPERTIES)
         self.instance.host = 'made-up-hostname'
@@ -93,6 +96,10 @@ class TestLocationMetadata(base.TestCase):
                 assert actual == iprops['image']['id']
             elif name == 'image_ref_url':
                 assert actual == iprops['image']['links'][0]['href']
+            elif name == 'user_metadata':
+                expected = iprops['metadata']['metering.autoscale.group'][:256]
+                self.assertEqual(actual['autoscale_group'], expected)
+                self.assertEqual(len(actual), 1)
             else:
                 assert actual == iprops[name]