diff --git a/devstack/README.md b/devstack/README.md
index 2ba21de3..56773db5 100644
--- a/devstack/README.md
+++ b/devstack/README.md
@@ -64,13 +64,13 @@ After finishing the installation, you can find the "Log Management" button on
 At first time, you need to specify the index pattern and time-field name.
 
 The index name is created as the following format.
-  \[mini-mon tenant id\]-YYYY-MM-DD
+  logs-\[mini-mon tenant id\]-YYYY-MM-DD
 For example:
-  20c4fbd37a2345dd84266dfc92da7bd1-2016-04-07
+  logs-20c4fbd37a2345dd84266dfc92da7bd1-2016-04-07
 
 Set the value as the above to index pattern.
 Or you can use "\*" as a wild card, like below.
-  20c4fbd37a2345dd84266dfc92da7bd1-\*
+  logs-20c4fbd37a2345dd84266dfc92da7bd1-\*
 
 Select @timestamp as time-field name.
 
diff --git a/devstack/files/monasca-log-persister/persister.conf b/devstack/files/monasca-log-persister/persister.conf
index ffcdeb7c..c0f581e3 100644
--- a/devstack/files/monasca-log-persister/persister.conf
+++ b/devstack/files/monasca-log-persister/persister.conf
@@ -63,7 +63,7 @@ filter {
 
 output {
     elasticsearch {
-        index => "%{tenant}-%{index_date}"
+        index => "logs-%{tenant}-%{index_date}"
         document_type => "log"
         hosts => ["%ES_SERVICE_BIND_HOST%"]
         flush_size => 500