diff --git a/config.go b/config.go
index be7203d36..43274a41d 100644
--- a/config.go
+++ b/config.go
@@ -86,3 +86,26 @@ func getConfigFile() (string, error) {
 	}
 	return filepath.Join(configPath, globalMinioConfigFile), nil
 }
+
+// isFormatConfigFileExists - returns true if format config file exists.
+func isFormatConfigFileExists() bool {
+	st, err := os.Stat(mustGetFormatConfigFile())
+	return (err == nil && st.Mode().IsRegular())
+}
+
+// mustGetFormatConfigFile must get format config file.
+func mustGetFormatConfigFile() string {
+	configFile, err := getFormatConfigFile()
+	fatalIf(err, "Unable to get format config file.", nil)
+
+	return configFile
+}
+
+// getFormatConfigFile get format config file.
+func getFormatConfigFile() (string, error) {
+	configPath, err := getConfigPath()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(configPath, globalMinioFormatConfigFile), nil
+}
diff --git a/format-config-v1.go b/format-config-v1.go
new file mode 100644
index 000000000..dabb75b0e
--- /dev/null
+++ b/format-config-v1.go
@@ -0,0 +1,111 @@
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import "github.com/minio/minio/pkg/quick"
+
+type fsFormat struct {
+	Version string `json:"version"`
+}
+
+type xlFormat struct {
+	Version string   `json:"version"`
+	Disks   []string `json:"disks"`
+}
+
+type formatConfigV1 struct {
+	// must have "Version" to "quick" to work
+	Version string   `json:"version"`
+	Format  string   `json:"format"`
+	FS      fsFormat `json:"fs,omitempty"`
+	XL      xlFormat `json:"xl,omitempty"`
+}
+
+func (f formatConfigV1) Save() error {
+	configFile, err := getFormatConfigFile()
+	if err != nil {
+		return err
+	}
+
+	// initialize quick.
+	qc, err := quick.New(&f)
+	if err != nil {
+		return err
+	}
+
+	// Save config file.
+	return qc.Save(configFile)
+}
+
+func (f *formatConfigV1) Load() error {
+	configFile, err := getFormatConfigFile()
+	if err != nil {
+		return err
+	}
+
+	f.Version = globalMinioConfigVersion
+	qc, err := quick.New(f)
+	if err != nil {
+		return err
+	}
+	if err := qc.Load(configFile); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// saveFormatFS - save FS format configuration
+func saveFormatFS(fs fsFormat) error {
+	config := formatConfigV1{Version: globalMinioConfigVersion, Format: "fs", FS: fs}
+	return config.Save()
+}
+
+// saveFormatXL - save XL format configuration
+func saveFormatXL(xl xlFormat) error {
+	config := formatConfigV1{Version: globalMinioConfigVersion, Format: "xl", XL: xl}
+	return config.Save()
+}
+
+// getSavedFormatConfig - get saved format configuration
+func getSavedFormatConfig() (formatConfigV1, error) {
+	config := formatConfigV1{Version: globalMinioConfigVersion}
+
+	if err := config.Load(); err != nil {
+		return config, err
+	}
+
+	return config, nil
+}
+
+// getFormatFS - get saved FS format configuration
+func getFormatFS() (fsFormat, error) {
+	config, err := getSavedFormatConfig()
+	if err != nil {
+		return fsFormat{}, err
+	}
+	return config.FS, nil
+}
+
+// getFormatXL - get saved XL format configuration
+func getFormatXL() (xlFormat, error) {
+	config, err := getSavedFormatConfig()
+	if err != nil {
+		return xlFormat{}, err
+	}
+	return config.XL, nil
+}
diff --git a/globals.go b/globals.go
index bb65c27bc..ad3b147f7 100644
--- a/globals.go
+++ b/globals.go
@@ -29,12 +29,13 @@ const (
 
 // minio configuration related constants.
 const (
-	globalMinioConfigVersion = "4"
-	globalMinioConfigDir     = ".minio"
-	globalMinioCertsDir      = ".minio/certs"
-	globalMinioCertFile      = "public.crt"
-	globalMinioKeyFile       = "private.key"
-	globalMinioConfigFile    = "config.json"
+	globalMinioConfigVersion    = "4"
+	globalMinioConfigDir        = ".minio"
+	globalMinioCertsDir         = ".minio/certs"
+	globalMinioCertFile         = "public.crt"
+	globalMinioKeyFile          = "private.key"
+	globalMinioConfigFile       = "config.json"
+	globalMinioFormatConfigFile = "format.json"
 )
 
 var (
diff --git a/routers.go b/routers.go
index 39afda7f7..5f5d9a7f3 100644
--- a/routers.go
+++ b/routers.go
@@ -17,7 +17,9 @@
 package main
 
 import (
+	"fmt"
 	"net/http"
+	"reflect"
 
 	router "github.com/gorilla/mux"
 )
@@ -36,6 +38,26 @@ func newObjectLayer(exportPaths ...string) (ObjectLayer, error) {
 
 // configureServer handler returns final handler for the http server.
 func configureServerHandler(srvCmdConfig serverCmdConfig) http.Handler {
+	// FIXME: currently we don't check single exportPath which uses FS layer.
+	if len(srvCmdConfig.exportPaths) > 1 {
+		if isFormatConfigFileExists() {
+			format, err := getFormatXL()
+			if err != nil {
+				fatalIf(err, "Failed to read format.json", nil)
+			}
+
+			if !reflect.DeepEqual(format.Disks, srvCmdConfig.exportPaths) {
+				err = fmt.Errorf("Number of export paths from command-line did not match the backend configuration. Backend is configured with [%s] exports.", format.Disks)
+				fatalIf(err, "", nil)
+			}
+		} else {
+			// First run: save disk configuration
+			if err := saveFormatXL(xlFormat{Version: "1", Disks: srvCmdConfig.exportPaths}); err != nil {
+				fatalIf(err, "Unable to save 'format.json'", nil)
+			}
+		}
+	}
+
 	objAPI, err := newObjectLayer(srvCmdConfig.exportPaths...)
 	fatalIf(err, "Initializing object layer failed.", nil)