diff --git a/weed/filer2/configuration.go b/weed/filer2/configuration.go
index 14a9edd2c..4b20b608b 100644
--- a/weed/filer2/configuration.go
+++ b/weed/filer2/configuration.go
@@ -13,6 +13,17 @@ var (
 
 func (f *Filer) LoadConfiguration(config *viper.Viper) {
 
+	enabledStore := ""
+	for _, store := range Stores {
+		if config.GetBool(store.GetName() + ".enabled") {
+			if enabledStore == "" {
+				enabledStore = store.GetName()
+			} else {
+				glog.Fatalf("Filer store is enabled for both %s and %s", enabledStore, store.GetName())
+			}
+		}
+	}
+
 	for _, store := range Stores {
 		if config.GetBool(store.GetName() + ".enabled") {
 			viperSub := config.Sub(store.GetName())