diff --git a/.travis.yml b/.travis.yml
index bd9c62698..7ec870ae0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,10 +1,24 @@
+sudo: false
 language: go
+
+os:
+- linux
+- osx
+
+osx_image: xcode7.2
+
+env:
+- ARCH=x86_64
+- ARCH=i686
+
 script:
 - make test
 - make test GOFLAGS="-race"
-sudo: false
+
 go:
-- 1.5.1
+- 1.5.2
+- 1.5.3
+
 notifications:
   slack:
     secure: K9tsn5MvrCAxuEZTxn+m3Kq1K2NG2xMEJFSv/sTp+RQBW7TslPHzv859GsIvrm8mU1y1btOU9RlOzqrRUczI5cJpE8IL1oljPZbXrIXgetE0kbsw0Wpy99g27UQ2VGp933WDu8tfj7zU4cZv+BI0RltNLwqYO6GWXmcWP0IueCU=
diff --git a/vendor.json b/vendor.json
deleted file mode 100755
index 8e8762e7b..000000000
--- a/vendor.json
+++ /dev/null
@@ -1,20 +0,0 @@
-{
-	"comment": "",
-	"ignore": "",
-	"package": [
-		{
-			"canonical": "github.com/minio/minio-xl/pkg/atomic",
-			"comment": "",
-			"local": "vendor/github.com/minio/minio-xl/pkg/atomic",
-			"revision": "a32fbc1006b4a09176c91f57d22e87faff22a423",
-			"revisionTime": "2015-11-17T22:59:41-08:00"
-		},
-		{
-			"canonical": "github.com/minio/minio-xl/pkg/quick",
-			"comment": "",
-			"local": "vendor/github.com/minio/minio-xl/pkg/quick",
-			"revision": "a32fbc1006b4a09176c91f57d22e87faff22a423",
-			"revisionTime": "2015-11-17T22:59:41-08:00"
-		}
-	]
-}
\ No newline at end of file
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows_386.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_darwin.go
similarity index 96%
rename from vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows_386.go
rename to vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_darwin.go
index 2e6757dbf..6dfb477fb 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows_386.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_darwin.go
@@ -1,3 +1,6 @@
+// +build 386 amd64 arm
+// +build darwin
+
 /*
  * Minio Cloud Storage, (C) 2014 Minio, Inc.
  *
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_386.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux.go
similarity index 97%
rename from vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_386.go
rename to vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux.go
index 4dc80c1dc..685fc9164 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_386.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux.go
@@ -1,3 +1,5 @@
+// +build 386 arm amd64,!cgo
+
 /*
  * Minio Cloud Storage, (C) 2015 Minio, Inc.
  *
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_amd64.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_amd64.go
index 07bca48f9..c6243ff95 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_amd64.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_amd64.go
@@ -1,3 +1,5 @@
+// +build amd64,cgo
+
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file of
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_amd64_test.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_amd64_test.go
index cc4bb6d08..3ac7ffb2e 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_amd64_test.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_amd64_test.go
@@ -1,3 +1,5 @@
+// +build amd64,cgo
+
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file of
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_arm.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_arm.go
deleted file mode 100644
index 4dc80c1dc..000000000
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_linux_arm.go
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2015 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 sha256
-
-import (
-	"hash"
-	"io"
-
-	"crypto/sha256"
-)
-
-// Sum256 - single caller sha256 helper
-func Sum256(data []byte) []byte {
-	d := sha256.New()
-	d.Write(data)
-	return d.Sum(nil)
-}
-
-// Sum - io.Reader based streaming sha256 helper
-func Sum(reader io.Reader) ([]byte, error) {
-	d := sha256.New()
-	var err error
-	for err == nil {
-		length := 0
-		byteBuffer := make([]byte, 1024*1024)
-		length, err = reader.Read(byteBuffer)
-		byteBuffer = byteBuffer[0:length]
-		d.Write(byteBuffer)
-	}
-	if err != io.EOF {
-		return nil, err
-	}
-	return d.Sum(nil), nil
-}
-
-// New returns a new hash.Hash computing SHA256.
-func New() hash.Hash {
-	return sha256.New()
-}
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_darwin_amd64.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows.go
similarity index 96%
rename from vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_darwin_amd64.go
rename to vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows.go
index 2e6757dbf..4585e2b75 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_darwin_amd64.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows.go
@@ -1,3 +1,6 @@
+// +build 386 amd64 arm
+// +build windows
+
 /*
  * Minio Cloud Storage, (C) 2014 Minio, Inc.
  *
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows_amd64.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows_amd64.go
deleted file mode 100644
index 2e6757dbf..000000000
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256_windows_amd64.go
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2014 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 sha256
-
-import (
-	"hash"
-	"io"
-
-	"crypto/sha256"
-)
-
-// Sum256 - single caller sha256 helper
-func Sum256(data []byte) []byte {
-	d := sha256.New()
-	d.Write(data)
-	return d.Sum(nil)
-}
-
-// Sum - io.Reader based streaming sha256 helper
-func Sum(reader io.Reader) ([]byte, error) {
-	d := sha256.New()
-	var err error
-	for err == nil {
-		length := 0
-		byteBuffer := make([]byte, 1024*1024)
-		length, err = reader.Read(byteBuffer)
-		byteBuffer = byteBuffer[0:length]
-		d.Write(byteBuffer)
-	}
-	if err != io.EOF {
-		return nil, err
-	}
-	return d.Sum(nil), nil
-}
-
-// New returns a new hash.Hash computing SHA256.
-func New() hash.Hash {
-	return sha256.New()
-}
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256block_linux_amd64.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256block_linux_amd64.go
index 26258e88e..1474589d4 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256block_linux_amd64.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha256/sha256block_linux_amd64.go
@@ -1,4 +1,4 @@
-// +build amd64
+// +build amd64,cgo
 
 //
 // Minio Cloud Storage, (C) 2015 Minio, Inc.
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_arm.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_darwin.go
similarity index 96%
rename from vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_arm.go
rename to vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_darwin.go
index 931e1a1a7..da971f4d4 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_arm.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_darwin.go
@@ -1,3 +1,6 @@
+// +build 386 amd64 arm
+// +build darwin
+
 /*
  * Minio Cloud Storage, (C) 2014 Minio, Inc.
  *
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_darwin_amd64.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_darwin_amd64.go
deleted file mode 100644
index 931e1a1a7..000000000
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_darwin_amd64.go
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2014 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 sha512
-
-import (
-	"hash"
-	"io"
-
-	"crypto/sha512"
-)
-
-// The size of a SHA512 checksum in bytes.
-const (
-	Size = sha512.Size
-)
-
-// Sum512 - single caller sha512 helper
-func Sum512(data []byte) []byte {
-	d := sha512.New()
-	d.Write(data)
-	return d.Sum(nil)
-}
-
-// Sum - io.Reader based streaming sha512 helper
-func Sum(reader io.Reader) ([]byte, error) {
-	d := sha512.New()
-	var err error
-	for err == nil {
-		length := 0
-		byteBuffer := make([]byte, 1024*1024)
-		length, err = reader.Read(byteBuffer)
-		byteBuffer = byteBuffer[0:length]
-		d.Write(byteBuffer)
-	}
-	if err != io.EOF {
-		return nil, err
-	}
-	return d.Sum(nil), nil
-}
-
-// New returns a new hash.Hash computing SHA512.
-func New() hash.Hash {
-	return sha512.New()
-}
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_386.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux.go
similarity index 97%
rename from vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_386.go
rename to vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux.go
index 931e1a1a7..a770813b9 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_386.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux.go
@@ -1,3 +1,5 @@
+// +build 386 arm amd64,!cgo
+
 /*
  * Minio Cloud Storage, (C) 2014 Minio, Inc.
  *
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_amd64.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_amd64.go
index 390d186f6..696a7d538 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_amd64.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_amd64.go
@@ -1,3 +1,5 @@
+// +build amd64,cgo
+
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file of
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_amd64_test.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_amd64_test.go
index f254cf605..6184c5b55 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_amd64_test.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_linux_amd64_test.go
@@ -1,3 +1,5 @@
+// +build amd64,cgo
+
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file of
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows_386.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows.go
similarity index 96%
rename from vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows_386.go
rename to vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows.go
index 931e1a1a7..bebd60967 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows_386.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows.go
@@ -1,3 +1,6 @@
+// +build 386 amd64 arm
+// +build windows
+
 /*
  * Minio Cloud Storage, (C) 2014 Minio, Inc.
  *
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows_amd64.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows_amd64.go
deleted file mode 100644
index 931e1a1a7..000000000
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512_windows_amd64.go
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Minio Cloud Storage, (C) 2014 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 sha512
-
-import (
-	"hash"
-	"io"
-
-	"crypto/sha512"
-)
-
-// The size of a SHA512 checksum in bytes.
-const (
-	Size = sha512.Size
-)
-
-// Sum512 - single caller sha512 helper
-func Sum512(data []byte) []byte {
-	d := sha512.New()
-	d.Write(data)
-	return d.Sum(nil)
-}
-
-// Sum - io.Reader based streaming sha512 helper
-func Sum(reader io.Reader) ([]byte, error) {
-	d := sha512.New()
-	var err error
-	for err == nil {
-		length := 0
-		byteBuffer := make([]byte, 1024*1024)
-		length, err = reader.Read(byteBuffer)
-		byteBuffer = byteBuffer[0:length]
-		d.Write(byteBuffer)
-	}
-	if err != io.EOF {
-		return nil, err
-	}
-	return d.Sum(nil), nil
-}
-
-// New returns a new hash.Hash computing SHA512.
-func New() hash.Hash {
-	return sha512.New()
-}
diff --git a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512block_linux_amd64.go b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512block_linux_amd64.go
index 03b47ccf1..80faf37bd 100644
--- a/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512block_linux_amd64.go
+++ b/vendor/github.com/minio/minio-xl/pkg/crypto/sha512/sha512block_linux_amd64.go
@@ -1,4 +1,4 @@
-// +build amd64
+// +build amd64,cgo
 
 //
 // Minio Cloud Storage, (C) 2015 Minio, Inc.
diff --git a/vendor/github.com/minio/minio-xl/pkg/quick/quick.go b/vendor/github.com/minio/minio-xl/pkg/quick/quick.go
index 92bb27b9a..ce4647eb5 100644
--- a/vendor/github.com/minio/minio-xl/pkg/quick/quick.go
+++ b/vendor/github.com/minio/minio-xl/pkg/quick/quick.go
@@ -72,8 +72,7 @@ func CheckData(data interface{}) *probe.Error {
 
 // New - instantiate a new config
 func New(data interface{}) (Config, *probe.Error) {
-	err := CheckData(data)
-	if err != nil {
+	if err := CheckData(data); err != nil {
 		return nil, err.Trace()
 	}
 
@@ -86,14 +85,14 @@ func New(data interface{}) (Config, *probe.Error) {
 // CheckVersion - loads json and compares the version number provided returns back true or false - any failure
 // is returned as error.
 func CheckVersion(filename string, version string) (bool, *probe.Error) {
-	_, err := os.Stat(filename)
-	if err != nil {
-		return false, probe.NewError(err)
+	_, e := os.Stat(filename)
+	if e != nil {
+		return false, probe.NewError(e)
 	}
 
-	fileData, err := ioutil.ReadFile(filename)
-	if err != nil {
-		return false, probe.NewError(err)
+	fileData, e := ioutil.ReadFile(filename)
+	if e != nil {
+		return false, probe.NewError(e)
 	}
 
 	if runtime.GOOS == "windows" {
@@ -104,18 +103,18 @@ func CheckVersion(filename string, version string) (bool, *probe.Error) {
 	}{
 		Version: "",
 	}
-	err = json.Unmarshal(fileData, &data)
-	if err != nil {
-		switch err := err.(type) {
+	e = json.Unmarshal(fileData, &data)
+	if e != nil {
+		switch e := e.(type) {
 		case *json.SyntaxError:
-			return false, probe.NewError(FormatJSONSyntaxError(bytes.NewReader(fileData), err))
+			return false, probe.NewError(FormatJSONSyntaxError(bytes.NewReader(fileData), e))
 		default:
-			return false, probe.NewError(err)
+			return false, probe.NewError(e)
 		}
 	}
-	config, perr := New(data)
-	if perr != nil {
-		return false, perr.Trace()
+	config, err := New(data)
+	if err != nil {
+		return false, err.Trace()
 	}
 	if config.Version() != version {
 		return false, nil
@@ -125,33 +124,33 @@ func CheckVersion(filename string, version string) (bool, *probe.Error) {
 
 // Load - loads json config from filename for the a given struct data
 func Load(filename string, data interface{}) (Config, *probe.Error) {
-	_, err := os.Stat(filename)
-	if err != nil {
-		return nil, probe.NewError(err)
+	_, e := os.Stat(filename)
+	if e != nil {
+		return nil, probe.NewError(e)
 	}
 
-	fileData, err := ioutil.ReadFile(filename)
-	if err != nil {
-		return nil, probe.NewError(err)
+	fileData, e := ioutil.ReadFile(filename)
+	if e != nil {
+		return nil, probe.NewError(e)
 	}
 
 	if runtime.GOOS == "windows" {
 		fileData = []byte(strings.Replace(string(fileData), "\r\n", "\n", -1))
 	}
 
-	err = json.Unmarshal(fileData, &data)
-	if err != nil {
-		switch err := err.(type) {
+	e = json.Unmarshal(fileData, &data)
+	if e != nil {
+		switch e := e.(type) {
 		case *json.SyntaxError:
-			return nil, probe.NewError(FormatJSONSyntaxError(bytes.NewReader(fileData), err))
+			return nil, probe.NewError(FormatJSONSyntaxError(bytes.NewReader(fileData), e))
 		default:
-			return nil, probe.NewError(err)
+			return nil, probe.NewError(e)
 		}
 	}
 
-	config, perr := New(data)
-	if perr != nil {
-		return nil, perr.Trace()
+	config, err := New(data)
+	if err != nil {
+		return nil, err.Trace()
 	}
 
 	return config, nil
@@ -174,6 +173,25 @@ func (d config) Version() string {
 	return ""
 }
 
+// writeFile writes data to a file named by filename.
+// If the file does not exist, writeFile creates it;
+// otherwise writeFile truncates it before writing.
+func writeFile(filename string, data []byte) *probe.Error {
+	atomicFile, e := atomic.FileCreate(filename)
+	if e != nil {
+		return probe.NewError(e)
+	}
+	_, e = atomicFile.Write(data)
+	if e != nil {
+		return probe.NewError(e)
+	}
+	e = atomicFile.Close()
+	if e != nil {
+		return probe.NewError(e)
+	}
+	return nil
+}
+
 // String converts JSON config to printable string
 func (d config) String() string {
 	configBytes, _ := json.MarshalIndent(d.data, "", "\t")
@@ -185,29 +203,42 @@ func (d config) Save(filename string) *probe.Error {
 	d.lock.Lock()
 	defer d.lock.Unlock()
 
-	jsonData, err := json.MarshalIndent(d.data, "", "\t")
-	if err != nil {
-		return probe.NewError(err)
+	// Check for existing file, if yes create a backup.
+	st, e := os.Stat(filename)
+	// If file exists and stat failed return here.
+	if e != nil && !os.IsNotExist(e) {
+		return probe.NewError(e)
+	}
+	// File exists and proceed to take backup.
+	if e == nil {
+		// File exists and is not a regular file return error.
+		if !st.Mode().IsRegular() {
+			return probe.NewError(fmt.Errorf("%s is not a regular file", filename))
+		}
+		// Read old data.
+		var oldData []byte
+		oldData, e = ioutil.ReadFile(filename)
+		if e != nil {
+			return probe.NewError(e)
+		}
+		// Save read data to the backup file.
+		if err := writeFile(filename+".old", oldData); err != nil {
+			return err.Trace(filename + ".old")
+		}
+	}
+	// Proceed to create or overwrite file.
+	jsonData, e := json.MarshalIndent(d.data, "", "\t")
+	if e != nil {
+		return probe.NewError(e)
 	}
 
 	if runtime.GOOS == "windows" {
 		jsonData = []byte(strings.Replace(string(jsonData), "\n", "\r\n", -1))
 	}
 
-	atomicFile, err := atomic.FileCreate(filename)
-	if err != nil {
-		return probe.NewError(err)
-	}
-	_, err = atomicFile.Write(jsonData)
-	if err != nil {
-		return probe.NewError(err)
-	}
-	err = atomicFile.Close()
-	if err != nil {
-		return probe.NewError(err)
-	}
-
-	return nil
+	// Save data.
+	err := writeFile(filename, jsonData)
+	return err.Trace(filename)
 }
 
 // Load - loads JSON config from file and merge with currently set values
@@ -215,14 +246,14 @@ func (d *config) Load(filename string) *probe.Error {
 	d.lock.Lock()
 	defer d.lock.Unlock()
 
-	_, err := os.Stat(filename)
-	if err != nil {
-		return probe.NewError(err)
+	_, e := os.Stat(filename)
+	if e != nil {
+		return probe.NewError(e)
 	}
 
-	fileData, err := ioutil.ReadFile(filename)
-	if err != nil {
-		return probe.NewError(err)
+	fileData, e := ioutil.ReadFile(filename)
+	if e != nil {
+		return probe.NewError(e)
 	}
 
 	if runtime.GOOS == "windows" {
@@ -235,18 +266,18 @@ func (d *config) Load(filename string) *probe.Error {
 		return probe.NewError(fmt.Errorf("Argument struct [%s] does not contain field \"Version\".", st.Name()))
 	}
 
-	err = json.Unmarshal(fileData, d.data)
-	if err != nil {
-		switch err := err.(type) {
+	e = json.Unmarshal(fileData, d.data)
+	if e != nil {
+		switch e := e.(type) {
 		case *json.SyntaxError:
-			return probe.NewError(FormatJSONSyntaxError(bytes.NewReader(fileData), err))
+			return probe.NewError(FormatJSONSyntaxError(bytes.NewReader(fileData), e))
 		default:
-			return probe.NewError(err)
+			return probe.NewError(e)
 		}
 	}
 
 	if err := CheckData(d.data); err != nil {
-		return err.Trace()
+		return err.Trace(filename)
 	}
 
 	if (*d).Version() != f.Value() {
diff --git a/vendor/github.com/minio/minio-xl/pkg/quick/quick_test.go b/vendor/github.com/minio/minio-xl/pkg/quick/quick_test.go
index babdc6d2e..7c0b05426 100644
--- a/vendor/github.com/minio/minio-xl/pkg/quick/quick_test.go
+++ b/vendor/github.com/minio/minio-xl/pkg/quick/quick_test.go
@@ -32,6 +32,21 @@ type MySuite struct{}
 
 var _ = Suite(&MySuite{})
 
+func (s *MySuite) TestSaveFailOnDir(c *C) {
+	defer os.RemoveAll("test.json")
+	e := os.MkdirAll("test.json", 0644)
+	c.Assert(e, IsNil)
+	type myStruct struct {
+		Version string
+	}
+	saveMe := myStruct{"1"}
+	config, err := quick.New(&saveMe)
+	c.Assert(err, IsNil)
+	c.Assert(config, Not(IsNil))
+	err = config.Save("test.json")
+	c.Assert(err, Not(IsNil))
+}
+
 func (s *MySuite) TestCheckData(c *C) {
 	err := quick.CheckData(nil)
 	c.Assert(err, Not(IsNil))
@@ -69,7 +84,8 @@ func (s *MySuite) TestVersion(c *C) {
 	config, err := quick.New(&saveMe)
 	c.Assert(err, IsNil)
 	c.Assert(config, Not(IsNil))
-	config.Save("test.json")
+	err = config.Save("test.json")
+	c.Assert(err, IsNil)
 
 	valid, err := quick.CheckVersion("test.json", "1")
 	c.Assert(err, IsNil)
@@ -92,19 +108,56 @@ func (s *MySuite) TestSaveLoad(c *C) {
 	config, err := quick.New(&saveMe)
 	c.Assert(err, IsNil)
 	c.Assert(config, Not(IsNil))
-	config.Save("test.json")
+	err = config.Save("test.json")
+	c.Assert(err, IsNil)
+
+	loadMe := myStruct{Version: "1"}
+	newConfig, err := quick.New(&loadMe)
+	c.Assert(err, IsNil)
+	c.Assert(newConfig, Not(IsNil))
+	err = newConfig.Load("test.json")
+	c.Assert(err, IsNil)
+
+	c.Assert(config.Data(), DeepEquals, newConfig.Data())
+	c.Assert(config.Data(), DeepEquals, &loadMe)
+
+	mismatch := myStruct{"1.1", "guest", "nopassword", []string{"Work", "Documents", "Music"}}
+	c.Assert(newConfig.Data(), Not(DeepEquals), &mismatch)
+}
+
+func (s *MySuite) TestSaveBackup(c *C) {
+	defer os.RemoveAll("test.json")
+	defer os.RemoveAll("test.json.old")
+	type myStruct struct {
+		Version  string
+		User     string
+		Password string
+		Folders  []string
+	}
+	saveMe := myStruct{"1", "guest", "nopassword", []string{"Work", "Documents", "Music"}}
+	config, err := quick.New(&saveMe)
+	c.Assert(err, IsNil)
+	c.Assert(config, Not(IsNil))
+	err = config.Save("test.json")
+	c.Assert(err, IsNil)
 
 	loadMe := myStruct{Version: "1"}
 	newConfig, err := quick.New(&loadMe)
 	c.Assert(err, IsNil)
 	c.Assert(newConfig, Not(IsNil))
-	newConfig.Load("test.json")
+	err = newConfig.Load("test.json")
+	c.Assert(err, IsNil)
 
 	c.Assert(config.Data(), DeepEquals, newConfig.Data())
 	c.Assert(config.Data(), DeepEquals, &loadMe)
 
 	mismatch := myStruct{"1.1", "guest", "nopassword", []string{"Work", "Documents", "Music"}}
 	c.Assert(newConfig.Data(), Not(DeepEquals), &mismatch)
+	config, err = quick.New(&mismatch)
+	c.Assert(err, IsNil)
+	c.Assert(config, Not(IsNil))
+	err = config.Save("test.json")
+	c.Assert(err, IsNil)
 }
 
 func (s *MySuite) TestDiff(c *C) {
diff --git a/vendor/vendor.json b/vendor/vendor.json
index 08ed412de..fd56a0860 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -39,8 +39,8 @@
 		},
 		{
 			"path": "github.com/minio/minio-xl/pkg/atomic",
-			"revision": "008404af67dcf66bdde580245cd43951b425ed39",
-			"revisionTime": "2015-11-17T16:21:42-08:00"
+			"revision": "69c47f638917ab1cb9e24649c84ac38e6f1891b8",
+			"revisionTime": "2016-01-14T18:12:05-08:00"
 		},
 		{
 			"path": "github.com/minio/minio-xl/pkg/cpu",
@@ -49,13 +49,13 @@
 		},
 		{
 			"path": "github.com/minio/minio-xl/pkg/crypto/sha256",
-			"revision": "a4e6504a5f94cf43bdbe3dec1a622317031b145d",
-			"revisionTime": "2015-11-14T00:48:52-08:00"
+			"revision": "69c47f638917ab1cb9e24649c84ac38e6f1891b8",
+			"revisionTime": "2016-01-14T18:12:05-08:00"
 		},
 		{
 			"path": "github.com/minio/minio-xl/pkg/crypto/sha512",
-			"revision": "a4e6504a5f94cf43bdbe3dec1a622317031b145d",
-			"revisionTime": "2015-11-14T00:48:52-08:00"
+			"revision": "69c47f638917ab1cb9e24649c84ac38e6f1891b8",
+			"revisionTime": "2016-01-14T18:12:05-08:00"
 		},
 		{
 			"path": "github.com/minio/minio-xl/pkg/minhttp",
@@ -69,8 +69,8 @@
 		},
 		{
 			"path": "github.com/minio/minio-xl/pkg/quick",
-			"revision": "008404af67dcf66bdde580245cd43951b425ed39",
-			"revisionTime": "2015-11-17T16:21:42-08:00"
+			"revision": "69c47f638917ab1cb9e24649c84ac38e6f1891b8",
+			"revisionTime": "2016-01-14T18:12:05-08:00"
 		},
 		{
 			"path": "github.com/rs/cors",