diff --git a/metadata/service/agent/single.yml b/metadata/service/agent/single.yml
index d9824e6..5b6c3d7 100644
--- a/metadata/service/agent/single.yml
+++ b/metadata/service/agent/single.yml
@@ -3,7 +3,8 @@
 classes:
  - service.fluentd.support
 parameters:
-  _param:
   fluentd:
     agent:
       enabled: true
+      dir:
+        positiondb: /var/lib/fluentd/positiondb