diff --git a/weed-fs/src/pkg/storage/needle.go b/weed-fs/src/pkg/storage/needle.go
index 346d476e5..8f014f73a 100644
--- a/weed-fs/src/pkg/storage/needle.go
+++ b/weed-fs/src/pkg/storage/needle.go
@@ -10,9 +10,8 @@ import (
 )
 
 type Needle struct {
-	Cookie       uint8  "random number to mitigate brute force lookups"
+	Cookie       uint32  "random number to mitigate brute force lookups"
 	Key          uint64 "file id"
-	AlternateKey uint32 "supplemental id"
 	Size         uint32 "Data size"
 	Data         []byte "The actual file data"
 	Checksum     int32  "CRC32 to check integrity"
@@ -36,32 +35,28 @@ func NewNeedle(r *http.Request) (n *Needle) {
 func (n *Needle) ParsePath(path string) {
 	a := strings.Split(path, "_")
 	log.Println("cookie", a[0], "key", a[1], "altKey", a[2])
-	cookie, _ := strconv.Atoi(a[0])
-	n.Cookie = uint8(cookie)
+	cookie, _ := strconv.Atoui(a[0])
+	n.Cookie = uint32(cookie)
 	n.Key, _ = strconv.Atoui64(a[1])
-	altKey, _ := strconv.Atoui64(a[2])
-	n.AlternateKey = uint32(altKey)
 }
 func (n *Needle) Append(w io.Writer) {
-	header := make([]byte, 17)
-	header[0] = n.Cookie
-	uint64toBytes(header[1:9], n.Key)
-	uint32toBytes(header[9:13], n.AlternateKey)
+	header := make([]byte, 16)
+    uint32toBytes(header[0:4], n.Cookie)
+	uint64toBytes(header[4:12], n.Key)
 	n.Size = uint32(len(n.Data))
-	uint32toBytes(header[13:17], n.Size)
+	uint32toBytes(header[12:16], n.Size)
 	w.Write(header)
 	w.Write(n.Data)
-	rest := 8 - ((n.Size + 17 + 4) % 8)
+	rest := 8 - ((n.Size + 16 + 4) % 8)
 	uint32toBytes(header[0:4], uint32(n.Checksum))
 	w.Write(header[0 : rest+4])
 }
 func (n *Needle) Read(r io.Reader, size uint32) {
-	bytes := make([]byte, size+17+4)
+	bytes := make([]byte, size+16+4)
 	r.Read(bytes)
-	n.Cookie = bytes[0]
-	n.Key = bytesToUint64(bytes[1:9])
-	n.AlternateKey = bytesToUint32(bytes[9:13])
-	n.Size = bytesToUint32(bytes[13:17])
-	n.Data = bytes[17 : 17+size]
-	n.Checksum = int32(bytesToUint32(bytes[17+size : 17+size+4]))
+	n.Cookie = bytesToUint32(bytes[0:4])
+	n.Key = bytesToUint64(bytes[4:12])
+	n.Size = bytesToUint32(bytes[12:16])
+	n.Data = bytes[16 : 16+size]
+	n.Checksum = int32(bytesToUint32(bytes[16+size : 16+size+4]))
 }
diff --git a/weed-fs/src/pkg/storage/needle_map.go b/weed-fs/src/pkg/storage/needle_map.go
index 6d0eecb74..3fbf1f6f5 100644
--- a/weed-fs/src/pkg/storage/needle_map.go
+++ b/weed-fs/src/pkg/storage/needle_map.go
@@ -6,7 +6,6 @@ import (
 
 type NeedleKey struct {
 	Key          uint64 "file id"
-	AlternateKey uint32 "supplemental id"
 }
 
 func (k *NeedleKey) String() string {
@@ -14,9 +13,6 @@ func (k *NeedleKey) String() string {
 	for i := uint(0); i < 8; i++ {
 		tmp[i] = byte(k.Key >> (8 * i))
 	}
-	for i := uint(0); i < 4; i++ {
-		tmp[i+8] = byte(k.AlternateKey >> (8 * i))
-	}
 	return string(tmp[:])
 }
 
@@ -26,28 +22,21 @@ type NeedleValue struct {
 }
 
 type NeedleMap struct {
-	m map[string]*NeedleValue //mapping NeedleKey(Key,AlternateKey) to NeedleValue
+	m map[uint64]*NeedleValue //mapping NeedleKey(Key,AlternateKey) to NeedleValue
 }
 
 func NewNeedleMap() *NeedleMap {
-	return &NeedleMap{m: make(map[string]*NeedleValue)}
+	return &NeedleMap{m: make(map[uint64]*NeedleValue)}
 }
 func (nm *NeedleMap) load(file *os.File) {
 }
-func makeKey(key uint64, altKey uint32) string {
-	var tmp [12]byte
-	for i := uint(0); i < 8; i++ {
-		tmp[i] = byte(key >> (8 * i))
-	}
-	for i := uint(0); i < 4; i++ {
-		tmp[i+8] = byte(altKey >> (8 * i))
-	}
-	return string(tmp[:])
+func makeKey(key uint64) uint64 {
+	return key
 }
-func (nm *NeedleMap) put(key uint64, altKey uint32, offset uint32, size uint32) {
-	nm.m[makeKey(key, altKey)] = &NeedleValue{Offset: offset, Size: size}
+func (nm *NeedleMap) put(key uint64, offset uint32, size uint32) {
+	nm.m[makeKey(key)] = &NeedleValue{Offset: offset, Size: size}
 }
-func (nm *NeedleMap) get(key uint64, altKey uint32) (element *NeedleValue, ok bool) {
-	element, ok = nm.m[makeKey(key, altKey)]
+func (nm *NeedleMap) get(key uint64) (element *NeedleValue, ok bool) {
+	element, ok = nm.m[makeKey(key)]
 	return
 }
diff --git a/weed-fs/src/pkg/storage/volume.go b/weed-fs/src/pkg/storage/volume.go
index f065233fe..dd1dff54e 100644
--- a/weed-fs/src/pkg/storage/volume.go
+++ b/weed-fs/src/pkg/storage/volume.go
@@ -52,15 +52,15 @@ func (v *Volume) write(n *Needle) {
 	counter := <-v.accessChannel
 	offset, _ := v.dataFile.Seek(0, 2)
 	n.Append(v.dataFile)
-	nv, ok := v.nm.get(n.Key, n.AlternateKey)
+	nv, ok := v.nm.get(n.Key)
 	if !ok || int64(nv.Offset)*8 < offset {
-		v.nm.put(n.Key, n.AlternateKey, uint32(offset/8), n.Size)
+		v.nm.put(n.Key, uint32(offset/8), n.Size)
 	}
 	v.accessChannel <- counter + 1
 }
 func (v *Volume) read(n *Needle) {
 	counter := <-v.accessChannel
-	nv, ok := v.nm.get(n.Key, n.AlternateKey)
+	nv, ok := v.nm.get(n.Key)
 	if ok && nv.Offset > 0 {
 		v.dataFile.Seek(int64(nv.Offset)*8, 0)
 		n.Read(v.dataFile, nv.Size)