diff --git a/src/flow/etc/oneflow-server.conf b/src/flow/etc/oneflow-server.conf
index acc8969f37..e56504e711 100644
--- a/src/flow/etc/oneflow-server.conf
+++ b/src/flow/etc/oneflow-server.conf
@@ -90,4 +90,9 @@
 # Log debug level
 #   0 = ERROR, 1 = WARNING, 2 = INFO, 3 = DEBUG
 #
-:debug_level: 2
+# System
+#   - file: log to log file
+#   - syslog: log to syslog
+:log:
+  :level: 2
+  :system: 'file'
diff --git a/src/onegate/etc/onegate-server.conf b/src/onegate/etc/onegate-server.conf
index 8d653ec792..6fdb17e01e 100644
--- a/src/onegate/etc/onegate-server.conf
+++ b/src/onegate/etc/onegate-server.conf
@@ -37,7 +37,12 @@
 # Log debug level
 #   0 = ERROR, 1 = WARNING, 2 = INFO, 3 = DEBUG
 #
-:debug_level: 3
+# System
+#   - file: log to log file
+#   - syslog: log to syslog
+:log:
+  :level: 2
+  :system: 'file'
 
 ################################################################################
 # Auth
diff --git a/src/sunstone/etc/sunstone-server.conf b/src/sunstone/etc/sunstone-server.conf
index 8b13e37a47..59c5a67450 100644
--- a/src/sunstone/etc/sunstone-server.conf
+++ b/src/sunstone/etc/sunstone-server.conf
@@ -67,7 +67,12 @@
 # Log debug level
 #   0 = ERROR, 1 = WARNING, 2 = INFO, 3 = DEBUG
 #
-:debug_level: 3
+# System
+#   - file: log to log file
+#   - syslog: log to syslog
+:log:
+  :level: 3
+  :system: 'file'
 
 ################################################################################
 # Proxy