diff --git a/nova/tests/unit/virt/libvirt/volume/test_vzstorage.py b/nova/tests/unit/virt/libvirt/volume/test_vzstorage.py
index ec0596d7a409..822ba08d6bd6 100644
--- a/nova/tests/unit/virt/libvirt/volume/test_vzstorage.py
+++ b/nova/tests/unit/virt/libvirt/volume/test_vzstorage.py
@@ -110,4 +110,4 @@ class LibvirtVZStorageTestCase(test_volume.LibvirtVolumeBaseTestCase):
         self.assertEqual('file', conf.source_type)
         self.assertEqual(file_path, conf.source_path)
         self.assertEqual('raw', conf.driver_format)
-        self.assertEqual('writethrough', conf.driver_cache)
+        self.assertEqual('writeback', conf.driver_cache)
diff --git a/nova/virt/libvirt/volume/vzstorage.py b/nova/virt/libvirt/volume/vzstorage.py
index d8b971e9542a..85ffb4507657 100644
--- a/nova/virt/libvirt/volume/vzstorage.py
+++ b/nova/virt/libvirt/volume/vzstorage.py
@@ -71,7 +71,7 @@ class LibvirtVZStorageVolumeDriver(fs.LibvirtBaseFileSystemVolumeDriver):
                      self).get_config(connection_info, disk_info)
 
         conf.source_type = 'file'
-        conf.driver_cache = 'writethrough'
+        conf.driver_cache = 'writeback'
         conf.source_path = connection_info['data']['device_path']
         conf.driver_format = connection_info['data'].get('format', 'raw')
         return conf