diff --git a/buildscripts/race.sh b/buildscripts/race.sh
index 66ee3de4a..7c34510ea 100755
--- a/buildscripts/race.sh
+++ b/buildscripts/race.sh
@@ -3,5 +3,5 @@
 set -e
 
 for d in $(go list ./... | grep -v browser); do
-    CGO_ENABLED=1 go test -v -race --timeout 50m "$d"
+    CGO_ENABLED=1 go test -v -race --timeout 100m "$d"
 done
diff --git a/cmd/fs-v1-helpers.go b/cmd/fs-v1-helpers.go
index 7009a3ed0..4aa216a38 100644
--- a/cmd/fs-v1-helpers.go
+++ b/cmd/fs-v1-helpers.go
@@ -271,8 +271,8 @@ func fsOpenFile(ctx context.Context, readPath string, offset int64) (io.ReadClos
 	return fr, st.Size(), nil
 }
 
-// Creates a file and copies data from incoming reader. Staging buffer is used by io.CopyBuffer.
-func fsCreateFile(ctx context.Context, filePath string, reader io.Reader, buf []byte, fallocSize int64) (int64, error) {
+// Creates a file and copies data from incoming reader.
+func fsCreateFile(ctx context.Context, filePath string, reader io.Reader, fallocSize int64) (int64, error) {
 	if filePath == "" || reader == nil {
 		logger.LogIf(ctx, errInvalidArgument)
 		return 0, errInvalidArgument
@@ -317,21 +317,10 @@ func fsCreateFile(ctx context.Context, filePath string, reader io.Reader, buf []
 		}
 	}
 
-	var bytesWritten int64
-	if buf != nil {
-		bytesWritten, err = io.CopyBuffer(writer, reader, buf)
-		if err != nil {
-			if err != io.ErrUnexpectedEOF {
-				logger.LogIf(ctx, err)
-			}
-			return 0, err
-		}
-	} else {
-		bytesWritten, err = io.Copy(writer, reader)
-		if err != nil {
-			logger.LogIf(ctx, err)
-			return 0, err
-		}
+	bytesWritten, err := io.Copy(writer, reader)
+	if err != nil {
+		logger.LogIf(ctx, err)
+		return 0, err
 	}
 
 	return bytesWritten, nil
diff --git a/cmd/fs-v1-helpers_test.go b/cmd/fs-v1-helpers_test.go
index 8344b913d..b2f42978f 100644
--- a/cmd/fs-v1-helpers_test.go
+++ b/cmd/fs-v1-helpers_test.go
@@ -75,7 +75,7 @@ func TestFSStats(t *testing.T) {
 	}
 
 	var reader = bytes.NewReader([]byte("Hello, world"))
-	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file"), reader, nil, 0); err != nil {
+	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file"), reader, 0); err != nil {
 		t.Fatalf("Unable to create file, %s", err)
 	}
 	// Seek back.
@@ -85,7 +85,7 @@ func TestFSStats(t *testing.T) {
 		t.Fatal("Unexpected error", err)
 	}
 
-	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "path/to/success-file"), reader, nil, 0); err != nil {
+	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "path/to/success-file"), reader, 0); err != nil {
 		t.Fatalf("Unable to create file, %s", err)
 	}
 	// Seek back.
@@ -192,7 +192,7 @@ func TestFSCreateAndOpen(t *testing.T) {
 		t.Fatalf("Unable to create directory, %s", err)
 	}
 
-	if _, err = fsCreateFile(GlobalContext, "", nil, nil, 0); err != errInvalidArgument {
+	if _, err = fsCreateFile(GlobalContext, "", nil, 0); err != errInvalidArgument {
 		t.Fatal("Unexpected error", err)
 	}
 
@@ -201,7 +201,7 @@ func TestFSCreateAndOpen(t *testing.T) {
 	}
 
 	var reader = bytes.NewReader([]byte("Hello, world"))
-	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file"), reader, nil, 0); err != nil {
+	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file"), reader, 0); err != nil {
 		t.Fatalf("Unable to create file, %s", err)
 	}
 	// Seek back.
@@ -229,7 +229,7 @@ func TestFSCreateAndOpen(t *testing.T) {
 	}
 
 	for i, testCase := range testCases {
-		_, err = fsCreateFile(GlobalContext, pathJoin(path, testCase.srcVol, testCase.srcPath), reader, nil, 0)
+		_, err = fsCreateFile(GlobalContext, pathJoin(path, testCase.srcVol, testCase.srcPath), reader, 0)
 		if err != testCase.expectedErr {
 			t.Errorf("Test case %d: Expected: \"%s\", got: \"%s\"", i+1, testCase.expectedErr, err)
 		}
@@ -258,9 +258,8 @@ func TestFSDeletes(t *testing.T) {
 		t.Fatalf("Unable to create directory, %s", err)
 	}
 
-	var buf = make([]byte, 4096)
 	var reader = bytes.NewReader([]byte("Hello, world"))
-	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file"), reader, buf, reader.Size()); err != nil {
+	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file"), reader, reader.Size()); err != nil {
 		t.Fatalf("Unable to create file, %s", err)
 	}
 	// Seek back.
@@ -396,13 +395,13 @@ func TestFSRemoves(t *testing.T) {
 	}
 
 	var reader = bytes.NewReader([]byte("Hello, world"))
-	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file"), reader, nil, 0); err != nil {
+	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file"), reader, 0); err != nil {
 		t.Fatalf("Unable to create file, %s", err)
 	}
 	// Seek back.
 	reader.Seek(0, 0)
 
-	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file-new"), reader, nil, 0); err != nil {
+	if _, err = fsCreateFile(GlobalContext, pathJoin(path, "success-vol", "success-file-new"), reader, 0); err != nil {
 		t.Fatalf("Unable to create file, %s", err)
 	}
 	// Seek back.
@@ -515,7 +514,7 @@ func TestFSRemoveMeta(t *testing.T) {
 	filePath := pathJoin(fsPath, "success-vol", "success-file")
 
 	var reader = bytes.NewReader([]byte("Hello, world"))
-	if _, err = fsCreateFile(GlobalContext, filePath, reader, nil, 0); err != nil {
+	if _, err = fsCreateFile(GlobalContext, filePath, reader, 0); err != nil {
 		t.Fatalf("Unable to create file, %s", err)
 	}
 
diff --git a/cmd/fs-v1-multipart.go b/cmd/fs-v1-multipart.go
index e1061c961..7744c07b4 100644
--- a/cmd/fs-v1-multipart.go
+++ b/cmd/fs-v1-multipart.go
@@ -313,14 +313,8 @@ func (fs *FSObjects) PutObjectPart(ctx context.Context, bucket, object, uploadID
 		return pi, toObjectErr(err, bucket, object)
 	}
 
-	bufSize := int64(readSizeV1)
-	if size := data.Size(); size > 0 && bufSize > size {
-		bufSize = size
-	}
-	buf := make([]byte, bufSize)
-
 	tmpPartPath := pathJoin(fs.fsPath, minioMetaTmpBucket, fs.fsUUID, uploadID+"."+mustGetUUID()+"."+strconv.Itoa(partID))
-	bytesWritten, err := fsCreateFile(ctx, tmpPartPath, data, buf, data.Size())
+	bytesWritten, err := fsCreateFile(ctx, tmpPartPath, data, data.Size())
 
 	// Delete temporary part in case of failure. If
 	// PutObjectPart succeeds then there would be nothing to
diff --git a/cmd/fs-v1.go b/cmd/fs-v1.go
index e5e3281d7..4517f9374 100644
--- a/cmd/fs-v1.go
+++ b/cmd/fs-v1.go
@@ -857,11 +857,6 @@ func (fs *FSObjects) getObject(ctx context.Context, bucket, object string, offse
 	}
 	defer reader.Close()
 
-	bufSize := int64(readSizeV1)
-	if length > 0 && bufSize > length {
-		bufSize = length
-	}
-
 	// For negative length we read everything.
 	if length < 0 {
 		length = size - offset
@@ -874,10 +869,7 @@ func (fs *FSObjects) getObject(ctx context.Context, bucket, object string, offse
 		return err
 	}
 
-	// Allocate a staging buffer.
-	buf := make([]byte, int(bufSize))
-
-	_, err = io.CopyBuffer(writer, io.LimitReader(reader, length), buf)
+	_, err = io.Copy(writer, io.LimitReader(reader, length))
 	// The writer will be closed incase of range queries, which will emit ErrClosedPipe.
 	if err == io.ErrClosedPipe {
 		err = nil
@@ -1199,15 +1191,8 @@ func (fs *FSObjects) putObject(ctx context.Context, bucket string, object string
 	// so that cleaning it up will be easy if the server goes down.
 	tempObj := mustGetUUID()
 
-	// Allocate a buffer to Read() from request body
-	bufSize := int64(readSizeV1)
-	if size := data.Size(); size > 0 && bufSize > size {
-		bufSize = size
-	}
-
-	buf := make([]byte, int(bufSize))
 	fsTmpObjPath := pathJoin(fs.fsPath, minioMetaTmpBucket, fs.fsUUID, tempObj)
-	bytesWritten, err := fsCreateFile(ctx, fsTmpObjPath, data, buf, data.Size())
+	bytesWritten, err := fsCreateFile(ctx, fsTmpObjPath, data, data.Size())
 
 	// Delete the temporary object in the case of a
 	// failure. If PutObject succeeds, then there would be
diff --git a/cmd/handler-api.go b/cmd/handler-api.go
index 849ea2986..3f98884ac 100644
--- a/cmd/handler-api.go
+++ b/cmd/handler-api.go
@@ -57,7 +57,7 @@ func (t *apiConfig) init(cfg api.Config, setDriveCount int) {
 		// max requests per node is calculated as
 		// total_ram / ram_per_request
 		// ram_per_request is 4MiB * setDriveCount + 2 * 10MiB (default erasure block size)
-		apiRequestsMaxPerNode = int(stats.TotalRAM / uint64(setDriveCount*readBlockSize+blockSizeV1*2))
+		apiRequestsMaxPerNode = int(stats.TotalRAM / uint64(setDriveCount*(writeBlockSize+readBlockSize)+blockSizeV1*2))
 	} else {
 		apiRequestsMaxPerNode = cfg.RequestsMax
 		if len(globalEndpoints.Hostnames()) > 0 {
diff --git a/cmd/object-api-common.go b/cmd/object-api-common.go
index e278ad3dc..d4ab9646d 100644
--- a/cmd/object-api-common.go
+++ b/cmd/object-api-common.go
@@ -31,9 +31,6 @@ const (
 	// Block size used for all internal operations version 1.
 	blockSizeV1 = 10 * humanize.MiByte
 
-	// Staging buffer read size for all internal operations version 1.
-	readSizeV1 = 1 * humanize.MiByte
-
 	// Buckets meta prefix.
 	bucketMetaPrefix = "buckets"
 
diff --git a/cmd/storage-rest-server.go b/cmd/storage-rest-server.go
index 01c050d7d..9d806ba81 100644
--- a/cmd/storage-rest-server.go
+++ b/cmd/storage-rest-server.go
@@ -515,15 +515,7 @@ func (s *storageRESTServer) ReadFileStreamHandler(w http.ResponseWriter, r *http
 	defer rc.Close()
 
 	w.Header().Set(xhttp.ContentLength, strconv.Itoa(length))
-
-	if length >= readBlockSize {
-		bufp := s.storage.pool.Get().(*[]byte)
-		defer s.storage.pool.Put(bufp)
-
-		io.CopyBuffer(w, rc, *bufp)
-	} else {
-		io.Copy(w, rc)
-	}
+	io.Copy(w, rc)
 	w.(http.Flusher).Flush()
 }
 
diff --git a/cmd/xl-storage.go b/cmd/xl-storage.go
index a896f987e..6418f50f1 100644
--- a/cmd/xl-storage.go
+++ b/cmd/xl-storage.go
@@ -55,7 +55,8 @@ import (
 const (
 	nullVersionID     = "null"
 	diskMinTotalSpace = 900 * humanize.MiByte // Min 900MiB total space.
-	readBlockSize     = 4 * humanize.MiByte   // Default read block size 4MiB.
+	writeBlockSize    = 4 * humanize.MiByte   // Default write block size 4MiB.
+	readBlockSize     = 2 * humanize.MiByte   // Default read block size 2MiB.
 
 	// On regular files bigger than this;
 	readAheadSize = 16 << 20
@@ -90,10 +91,11 @@ type xlStorage struct {
 	diskPath string
 	endpoint Endpoint
 
-	pool sync.Pool
-
 	globalSync bool
 
+	wpool sync.Pool
+	rpool sync.Pool
+
 	rootDisk bool
 
 	diskID string
@@ -254,7 +256,13 @@ func newXLStorage(ep Endpoint) (*xlStorage, error) {
 	p := &xlStorage{
 		diskPath: path,
 		endpoint: ep,
-		pool: sync.Pool{
+		wpool: sync.Pool{
+			New: func() interface{} {
+				b := disk.AlignedBlock(writeBlockSize)
+				return &b
+			},
+		},
+		rpool: sync.Pool{
 			New: func() interface{} {
 				b := disk.AlignedBlock(readBlockSize)
 				return &b
@@ -671,12 +679,16 @@ func (s *xlStorage) StatVol(ctx context.Context, volume string) (vol VolInfo, er
 	var st os.FileInfo
 	st, err = os.Stat(volumeDir)
 	if err != nil {
-		if osIsNotExist(err) {
+		switch {
+		case osIsNotExist(err):
 			return VolInfo{}, errVolumeNotFound
-		} else if isSysErrIO(err) {
+		case osIsPermission(err):
+			return VolInfo{}, errDiskAccessDenied
+		case isSysErrIO(err):
 			return VolInfo{}, errFaultyDisk
+		default:
+			return VolInfo{}, err
 		}
-		return VolInfo{}, err
 	}
 	// As os.Stat() doesn't carry other than ModTime(), use ModTime()
 	// as CreatedTime.
@@ -723,58 +735,6 @@ func (s *xlStorage) DeleteVol(ctx context.Context, volume string, forceDelete bo
 	return nil
 }
 
-const guidSplunk = "guidSplunk"
-
-// ListDirSplunk - return all the entries at the given directory path.
-// If an entry is a directory it will be returned with a trailing SlashSeparator.
-func (s *xlStorage) ListDirSplunk(volume, dirPath string, count int) (entries []string, err error) {
-	guidIndex := strings.Index(dirPath, guidSplunk)
-	if guidIndex != -1 {
-		return nil, nil
-	}
-
-	atomic.AddInt32(&s.activeIOCount, 1)
-	defer func() {
-		atomic.AddInt32(&s.activeIOCount, -1)
-	}()
-
-	// Verify if volume is valid and it exists.
-	volumeDir, err := s.getVolDir(volume)
-	if err != nil {
-		return nil, err
-	}
-
-	if _, err = os.Stat(volumeDir); err != nil {
-		if osIsNotExist(err) {
-			return nil, errVolumeNotFound
-		} else if isSysErrIO(err) {
-			return nil, errFaultyDisk
-		}
-		return nil, err
-	}
-
-	dirPathAbs := pathJoin(volumeDir, dirPath)
-	if count > 0 {
-		entries, err = readDirN(dirPathAbs, count)
-	} else {
-		entries, err = readDir(dirPathAbs)
-	}
-	if err != nil {
-		return nil, err
-	}
-
-	return entries, nil
-}
-
-func (s *xlStorage) isLeafSplunk(volume string, leafPath string) bool {
-	const receiptJSON = "receipt.json"
-
-	if path.Base(leafPath) != receiptJSON {
-		return false
-	}
-	return s.isLeaf(volume, leafPath)
-}
-
 func (s *xlStorage) isLeaf(volume string, leafPath string) bool {
 	volumeDir, err := s.getVolDir(volume)
 	if err != nil {
@@ -903,15 +863,6 @@ func (s *xlStorage) ListDir(ctx context.Context, volume, dirPath string, count i
 		return nil, err
 	}
 
-	if _, err = os.Stat(volumeDir); err != nil {
-		if osIsNotExist(err) {
-			return nil, errVolumeNotFound
-		} else if isSysErrIO(err) {
-			return nil, errFaultyDisk
-		}
-		return nil, err
-	}
-
 	dirPathAbs := pathJoin(volumeDir, dirPath)
 	if count > 0 {
 		entries, err = readDirN(dirPathAbs, count)
@@ -919,6 +870,15 @@ func (s *xlStorage) ListDir(ctx context.Context, volume, dirPath string, count i
 		entries, err = readDir(dirPathAbs)
 	}
 	if err != nil {
+		if err == errFileNotFound {
+			if _, verr := os.Stat(volumeDir); verr != nil {
+				if osIsNotExist(verr) {
+					return nil, errVolumeNotFound
+				} else if isSysErrIO(verr) {
+					return nil, errFaultyDisk
+				}
+			}
+		}
 		return nil, err
 	}
 
@@ -1122,8 +1082,6 @@ func (s *xlStorage) renameLegacyMetadata(volume, path string) error {
 }
 
 // ReadVersion - reads metadata and returns FileInfo at path `xl.meta`
-// for all objects less than `128KiB` this call returns data as well
-// along with metadata.
 func (s *xlStorage) ReadVersion(ctx context.Context, volume, path, versionID string) (fi FileInfo, err error) {
 	buf, err := s.ReadAll(ctx, volume, pathJoin(path, xlStorageFormatFile))
 	if err != nil {
@@ -1300,11 +1258,8 @@ func (s *xlStorage) ReadFile(ctx context.Context, volume string, path string, of
 		return int64(n), err
 	}
 
-	bufp := s.pool.Get().(*[]byte)
-	defer s.pool.Put(bufp)
-
 	h := verifier.algorithm.New()
-	if _, err = io.CopyBuffer(h, io.LimitReader(file, offset), *bufp); err != nil {
+	if _, err = io.Copy(h, io.LimitReader(file, offset)); err != nil {
 		return 0, err
 	}
 
@@ -1316,7 +1271,7 @@ func (s *xlStorage) ReadFile(ctx context.Context, volume string, path string, of
 		return 0, err
 	}
 
-	if _, err = io.CopyBuffer(h, file, *bufp); err != nil {
+	if _, err = io.Copy(h, file); err != nil {
 		return 0, err
 	}
 
@@ -1384,7 +1339,7 @@ func (s *xlStorage) openFile(volume, path string, mode int) (f *os.File, err err
 }
 
 // To support O_DIRECT reads for erasure backends.
-type odirectreader struct {
+type odirectReader struct {
 	f         *os.File
 	buf       []byte
 	bufp      *[]byte
@@ -1394,12 +1349,12 @@ type odirectreader struct {
 }
 
 // Read - Implements Reader interface.
-func (o *odirectreader) Read(buf []byte) (n int, err error) {
+func (o *odirectReader) Read(buf []byte) (n int, err error) {
 	if o.err != nil {
 		return 0, o.err
 	}
 	if o.buf == nil {
-		o.bufp = o.s.pool.Get().(*[]byte)
+		o.bufp = o.s.rpool.Get().(*[]byte)
 	}
 	if o.freshRead {
 		o.buf = *o.bufp
@@ -1427,8 +1382,8 @@ func (o *odirectreader) Read(buf []byte) (n int, err error) {
 }
 
 // Close - Release the buffer and close the file.
-func (o *odirectreader) Close() error {
-	o.s.pool.Put(o.bufp)
+func (o *odirectReader) Close() error {
+	o.s.rpool.Put(o.bufp)
 	atomic.AddInt32(&o.s.activeIOCount, -1)
 	return o.f.Close()
 }
@@ -1474,7 +1429,7 @@ func (s *xlStorage) ReadFileStream(ctx context.Context, volume, path string, off
 		}
 
 		atomic.AddInt32(&s.activeIOCount, 1)
-		return &odirectreader{file, nil, nil, true, s, nil}, nil
+		return &odirectReader{file, nil, nil, true, s, nil}, nil
 	}
 
 	// Open the file for reading.
@@ -1640,8 +1595,8 @@ func (s *xlStorage) CreateFile(ctx context.Context, volume, path string, fileSiz
 		w.Close()
 	}()
 
-	bufp := s.pool.Get().(*[]byte)
-	defer s.pool.Put(bufp)
+	bufp := s.wpool.Get().(*[]byte)
+	defer s.wpool.Put(bufp)
 
 	written, err := xioutil.CopyAligned(w, r, *bufp, fileSize)
 	if err != nil {
@@ -2271,11 +2226,8 @@ func (s *xlStorage) bitrotVerify(partPath string, partSize int64, algo BitrotAlg
 	defer file.Close()
 
 	if algo != HighwayHash256S {
-		bufp := s.pool.Get().(*[]byte)
-		defer s.pool.Put(bufp)
-
 		h := algo.New()
-		if _, err = io.CopyBuffer(h, file, *bufp); err != nil {
+		if _, err = io.Copy(h, file); err != nil {
 			// Premature failure in reading the object,file is corrupt.
 			return errFileCorrupt
 		}
diff --git a/cmd/xl-storage_test.go b/cmd/xl-storage_test.go
index 97ec5eb18..108d7c8fb 100644
--- a/cmd/xl-storage_test.go
+++ b/cmd/xl-storage_test.go
@@ -703,8 +703,8 @@ func TestXLStorageListVols(t *testing.T) {
 	}
 }
 
-// TestXLStorageXlStorageListDir -  TestXLStorages validate the directory listing functionality provided by xlStorage.ListDir .
-func TestXLStorageXlStorageListDir(t *testing.T) {
+// TestXLStorageListDir -  TestXLStorages validate the directory listing functionality provided by xlStorage.ListDir .
+func TestXLStorageListDir(t *testing.T) {
 	// create xlStorage test setup
 	xlStorage, path, err := newXLStorageTestSetup()
 	if err != nil {
@@ -1692,8 +1692,9 @@ func TestXLStorageVerifyFile(t *testing.T) {
 	w := newStreamingBitrotWriter(xlStorage, volName, fileName, size, algo, shardSize)
 	reader := bytes.NewReader(data)
 	for {
-		// Using io.CopyBuffer instead of this loop will not work for us as io.CopyBuffer
-		// will use bytes.Buffer.ReadConfig() which will not do shardSize'ed writes causing error.
+		// Using io.Copy instead of this loop will not work for us as io.Copy
+		// will use bytes.Reader.WriteTo() which will not do shardSize'ed writes
+		// causing error.
 		n, err := reader.Read(shard)
 		w.Write(shard[:n])
 		if err == nil {
diff --git a/docs/shared-backend/DESIGN.md b/docs/shared-backend/DESIGN.md
index e50df2c19..b7220fffa 100644
--- a/docs/shared-backend/DESIGN.md
+++ b/docs/shared-backend/DESIGN.md
@@ -90,7 +90,7 @@ GetObject() holds a read lock on `fs.json`.
 
 ... you can perform other operations here ...
 
-	_, err = io.CopyBuffer(writer, reader, buf)
+	_, err = io.Copy(writer, reader)
 
 ... after successful copy operation unlocks the read lock ...
 ```
diff --git a/docs/zh_CN/shared-backend/DESIGN.md b/docs/zh_CN/shared-backend/DESIGN.md
index 4c51390ee..8757872ec 100644
--- a/docs/zh_CN/shared-backend/DESIGN.md
+++ b/docs/zh_CN/shared-backend/DESIGN.md
@@ -38,7 +38,7 @@ minio server /path/to/nfs-volume
 
 ### Windows 2012 Server
 
-示例1: 运行Minio实例在持载在`\\remote-server\cifs`路径下的共享后端存储。 
+示例1: 运行Minio实例在持载在`\\remote-server\cifs`路径下的共享后端存储。
 
 On windows server1
 ```cmd
@@ -94,7 +94,7 @@ GetObject()持有`fs.json`的一个读锁。
 
 ... you can perform other operations here ...
 
-	_, err = io.CopyBuffer(writer, reader, buf)
+	_, err = io.Copy(writer, reader)
 
 ... after successful copy operation unlocks the read lock ...
 ```
diff --git a/pkg/ioutil/append-file_nix.go b/pkg/ioutil/append-file_nix.go
index 468c185d0..3e60383dc 100644
--- a/pkg/ioutil/append-file_nix.go
+++ b/pkg/ioutil/append-file_nix.go
@@ -40,8 +40,6 @@ func AppendFile(dst string, src string, osync bool) error {
 		return err
 	}
 	defer srcFile.Close()
-	// Allocate staging buffer.
-	var buf = make([]byte, defaultAppendBufferSize)
-	_, err = io.CopyBuffer(appendFile, srcFile, buf)
+	_, err = io.Copy(appendFile, srcFile)
 	return err
 }
diff --git a/pkg/ioutil/append-file_windows.go b/pkg/ioutil/append-file_windows.go
index ee23bb03b..c93cb5fd5 100644
--- a/pkg/ioutil/append-file_windows.go
+++ b/pkg/ioutil/append-file_windows.go
@@ -36,8 +36,6 @@ func AppendFile(dst string, src string, osync bool) error {
 		return err
 	}
 	defer srcFile.Close()
-	// Allocate staging buffer.
-	var buf = make([]byte, defaultAppendBufferSize)
-	_, err = io.CopyBuffer(appendFile, srcFile, buf)
+	_, err = io.Copy(appendFile, srcFile)
 	return err
 }
diff --git a/pkg/ioutil/ioutil.go b/pkg/ioutil/ioutil.go
index 6c66c3859..d034c611d 100644
--- a/pkg/ioutil/ioutil.go
+++ b/pkg/ioutil/ioutil.go
@@ -22,13 +22,9 @@ import (
 	"io"
 	"os"
 
-	humanize "github.com/dustin/go-humanize"
 	"github.com/minio/minio/pkg/disk"
 )
 
-// defaultAppendBufferSize - Default buffer size for the AppendFile
-const defaultAppendBufferSize = humanize.MiByte
-
 // WriteOnCloser implements io.WriteCloser and always
 // executes at least one write operation if it is closed.
 //
@@ -186,7 +182,7 @@ const directioAlignSize = 4096
 // 4K page boundaries. Without passing aligned buffer may cause
 // this function to return error.
 //
-// This code is similar in spirit to io.CopyBuffer but it is only to be
+// This code is similar in spirit to io.Copy but it is only to be
 // used with DIRECT I/O based file descriptor and it is expected that
 // input writer *os.File not a generic io.Writer. Make sure to have
 // the file opened for writes with syscall.O_DIRECT flag.