diff --git a/blazar/plugins/instances/instance_plugin.py b/blazar/plugins/instances/instance_plugin.py
index 5136a58f..8b2be7b7 100644
--- a/blazar/plugins/instances/instance_plugin.py
+++ b/blazar/plugins/instances/instance_plugin.py
@@ -257,7 +257,43 @@ class VirtualInstancePlugin(base.BasePlugin, nova.NovaClientWrapper):
                                   "support updates of reservation.")
 
     def on_start(self, resource_id):
-        pass
+        ctx = context.current()
+        instance_reservation = db_api.instance_reservation_get(resource_id)
+        reservation_id = instance_reservation['reservation_id']
+
+        try:
+            self.nova.flavor_access.add_tenant_access(reservation_id,
+                                                      ctx.project_id)
+        except nova_exceptions.ClientException:
+            LOG.info('Failed to associate flavor %s to project %s' %
+                     (reservation_id, ctx.project_id))
+            raise mgr_exceptions.EventError()
+
+        pool = nova.ReservationPool()
+        for allocation in db_api.host_allocation_get_all_by_values(
+                reservation_id=reservation_id):
+            host = db_api.host_get(allocation['compute_host_id'])
+            pool.add_computehost(instance_reservation['aggregate_id'],
+                                 host['service_name'], stay_in=True)
 
     def on_end(self, resource_id):
-        pass
+        instance_reservation = db_api.instance_reservation_get(resource_id)
+        ctx = context.current()
+
+        try:
+            self.nova.flavor_access.remove_tenant_access(
+                instance_reservation['reservation_id'], ctx.project_id)
+        except nova_exceptions.NotFound:
+            pass
+
+        allocations = db_api.host_allocation_get_all_by_values(
+            reservation_id=instance_reservation['reservation_id'])
+        for allocation in allocations:
+            db_api.host_allocation_destroy(allocation['id'])
+
+        for server in self.nova.servers.list(search_opts={
+                'flavor': instance_reservation['reservation_id'],
+                'all_tenants': 1}, detailed=False):
+            server.delete()
+
+        self.cleanup_resources(instance_reservation)
diff --git a/blazar/tests/plugins/instances/test_instance_plugin.py b/blazar/tests/plugins/instances/test_instance_plugin.py
index 941801f2..b931f05b 100644
--- a/blazar/tests/plugins/instances/test_instance_plugin.py
+++ b/blazar/tests/plugins/instances/test_instance_plugin.py
@@ -444,3 +444,75 @@ class TestVirtualInstancePlugin(tests.TestCase):
             metadata={'reservation': 'reservation-id1',
                       'filter_tenant_id': 'fake-project',
                       'affinity_id': 'server_group_id1'})
+
+    def test_on_start(self):
+        def fake_host_get(host_id):
+            return {'service_name': 'host' + host_id[-1]}
+
+        self.set_context(context.BlazarContext(project_id='fake-project'))
+        plugin = instance_plugin.VirtualInstancePlugin()
+
+        mock_inst_get = self.patch(db_api, 'instance_reservation_get')
+        mock_inst_get.return_value = {'reservation_id': 'reservation-id1',
+                                      'aggregate_id': 'aggregate-id1'}
+
+        mock_nova = mock.MagicMock()
+        type(plugin).nova = mock_nova
+
+        fake_pool = mock.MagicMock()
+        mock_pool = self.patch(nova, 'ReservationPool')
+        mock_pool.return_value = fake_pool
+
+        mock_alloc_get = self.patch(db_api,
+                                    'host_allocation_get_all_by_values')
+        mock_alloc_get.return_value = [
+            {'compute_host_id': 'host-id1'}, {'compute_host_id': 'host-id2'},
+            {'compute_host_id': 'host-id3'}]
+
+        mock_host_get = self.patch(db_api, 'host_get')
+        mock_host_get.side_effect = fake_host_get
+
+        plugin.on_start('resource-id1')
+
+        mock_nova.flavor_access.add_tenant_access.assert_called_once_with(
+            'reservation-id1', 'fake-project')
+        for i in range(3):
+            fake_pool.add_computehost.assert_any_call('aggregate-id1',
+                                                      'host' + str(i + 1),
+                                                      stay_in=True)
+
+    def test_on_end(self):
+        self.set_context(context.BlazarContext(project_id='fake-project-id'))
+
+        plugin = instance_plugin.VirtualInstancePlugin()
+
+        fake_instance_reservation = {'reservation_id': 'reservation-id1'}
+        mock_inst_get = self.patch(db_api, 'instance_reservation_get')
+        mock_inst_get.return_value = fake_instance_reservation
+
+        mock_alloc_get = self.patch(db_api,
+                                    'host_allocation_get_all_by_values')
+        mock_alloc_get.return_value = [{'id': 'host-alloc-id1'},
+                                       {'id': 'host-alloc-id2'}]
+
+        self.patch(db_api, 'host_allocation_destroy')
+
+        fake_servers = [mock.MagicMock(method='delete') for i in range(5)]
+        mock_nova = mock.MagicMock()
+        type(plugin).nova = mock_nova
+        mock_nova.servers.list.return_value = fake_servers
+
+        mock_cleanup_resources = self.patch(plugin, 'cleanup_resources')
+
+        plugin.on_end('resource-id1')
+
+        mock_nova.flavor_access.remove_tenant_access.assert_called_once_with(
+            'reservation-id1', 'fake-project-id')
+
+        mock_nova.servers.list.assert_called_once_with(
+            search_opts={'flavor': 'reservation-id1', 'all_tenants': 1},
+            detailed=False)
+        for fake in fake_servers:
+            fake.delete.assert_called_once()
+        mock_cleanup_resources.assert_called_once_with(
+            fake_instance_reservation)
diff --git a/blazar/utils/openstack/nova.py b/blazar/utils/openstack/nova.py
index 99d022f7..58d07e3e 100644
--- a/blazar/utils/openstack/nova.py
+++ b/blazar/utils/openstack/nova.py
@@ -323,7 +323,7 @@ class ReservationPool(NovaClientWrapper):
         except manager_exceptions.AggregateNotFound:
             return []
 
-    def add_computehost(self, pool, host):
+    def add_computehost(self, pool, host, stay_in=False):
         """Add a compute host to an aggregate.
 
         The `host` must exist otherwise raise an error
@@ -344,7 +344,7 @@ class ReservationPool(NovaClientWrapper):
         except manager_exceptions.AggregateNotFound:
             raise manager_exceptions.NoFreePool()
 
-        if freepool_agg.id != agg.id:
+        if freepool_agg.id != agg.id and not stay_in:
             if host not in freepool_agg.hosts:
                 raise manager_exceptions.HostNotInFreePool(
                     host=host, freepool_name=freepool_agg.name)