diff --git a/weed-fs/src/pkg/storage/needle.go b/weed-fs/src/pkg/storage/needle.go
index 28dfbbed6..ffa9beb06 100644
--- a/weed-fs/src/pkg/storage/needle.go
+++ b/weed-fs/src/pkg/storage/needle.go
@@ -2,13 +2,10 @@ package storage
 
 import (
 	"encoding/hex"
-	"errors"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"mime"
 	"net/http"
-	"os"
 	"pkg/util"
 	"strconv"
 	"strings"
@@ -89,53 +86,14 @@ func (n *Needle) ParsePath(fid string) {
 		}
 	}
 }
-func (n *Needle) Append(w io.Writer) uint32 {
-	header := make([]byte, 16)
-	util.Uint32toBytes(header[0:4], n.Cookie)
-	util.Uint64toBytes(header[4:12], n.Id)
-	n.Size = uint32(len(n.Data))
-	util.Uint32toBytes(header[12:16], n.Size)
-	w.Write(header)
-	w.Write(n.Data)
-	rest := 8 - ((n.Size + 16 + 4) % 8)
-	util.Uint32toBytes(header[0:4], n.Checksum.Value())
-	w.Write(header[0 : rest+4])
-	return n.Size
-}
-func (n *Needle) Read(r io.Reader, size uint32, version Version) (int, error) {
-	bytes := make([]byte, size+16+4)
-	ret, e := r.Read(bytes)
-	n.Cookie = util.BytesToUint32(bytes[0:4])
-	n.Id = util.BytesToUint64(bytes[4:12])
-	n.Size = util.BytesToUint32(bytes[12:16])
-	n.Data = bytes[16 : 16+size]
-	checksum := util.BytesToUint32(bytes[16+size : 16+size+4])
-	if checksum != NewCRC(n.Data).Value() {
-		return 0, errors.New("CRC error! Data On Disk Corrupted!")
-	}
-	return ret, e
-}
-func ReadNeedle(r *os.File) (*Needle, uint32) {
-	n := new(Needle)
-	bytes := make([]byte, 16)
-	count, e := r.Read(bytes)
-	if count <= 0 || e != nil {
-		return nil, 0
-	}
-	n.Cookie = util.BytesToUint32(bytes[0:4])
-	n.Id = util.BytesToUint64(bytes[4:12])
-	n.Size = util.BytesToUint32(bytes[12:16])
-	rest := 8 - ((n.Size + 16 + 4) % 8)
-	return n, n.Size + 4 + rest
-}
 func ParseKeyHash(key_hash_string string) (uint64, uint32) {
-	key_hash_bytes, khe := hex.DecodeString(key_hash_string)
-	key_hash_len := len(key_hash_bytes)
-	if khe != nil || key_hash_len <= 4 {
-		println("Invalid key_hash", key_hash_string, "length:", key_hash_len, "error", khe)
-		return 0, 0
-	}
-	key := util.BytesToUint64(key_hash_bytes[0 : key_hash_len-4])
-	hash := util.BytesToUint32(key_hash_bytes[key_hash_len-4 : key_hash_len])
-	return key, hash
+    key_hash_bytes, khe := hex.DecodeString(key_hash_string)
+    key_hash_len := len(key_hash_bytes)
+    if khe != nil || key_hash_len <= 4 {
+        println("Invalid key_hash", key_hash_string, "length:", key_hash_len, "error", khe)
+        return 0, 0
+    }
+    key := util.BytesToUint64(key_hash_bytes[0 : key_hash_len-4])
+    hash := util.BytesToUint32(key_hash_bytes[key_hash_len-4 : key_hash_len])
+    return key, hash
 }
diff --git a/weed-fs/src/pkg/storage/needle_read_write.go b/weed-fs/src/pkg/storage/needle_read_write.go
new file mode 100644
index 000000000..bd0bebd0b
--- /dev/null
+++ b/weed-fs/src/pkg/storage/needle_read_write.go
@@ -0,0 +1,52 @@
+package storage
+
+import (
+    "errors"
+	"io"
+	"os"
+	"pkg/util"
+)
+
+func (n *Needle) Append(w io.Writer) uint32 {
+	header := make([]byte, 16)
+	util.Uint32toBytes(header[0:4], n.Cookie)
+	util.Uint64toBytes(header[4:12], n.Id)
+	n.Size = uint32(len(n.Data))
+	util.Uint32toBytes(header[12:16], n.Size)
+	w.Write(header)
+	w.Write(n.Data)
+	rest := 8 - ((n.Size + 16 + 4) % 8)
+	util.Uint32toBytes(header[0:4], n.Checksum.Value())
+	w.Write(header[0 : rest+4])
+	return n.Size
+}
+func (n *Needle) Read(r io.Reader, size uint32, version Version) (int, error) {
+	if version == Version1 {
+		bytes := make([]byte, size+16+4)
+		ret, e := r.Read(bytes)
+		n.Cookie = util.BytesToUint32(bytes[0:4])
+		n.Id = util.BytesToUint64(bytes[4:12])
+		n.Size = util.BytesToUint32(bytes[12:16])
+		n.Data = bytes[16 : 16+size]
+		checksum := util.BytesToUint32(bytes[16+size : 16+size+4])
+		if checksum != NewCRC(n.Data).Value() {
+			return 0, errors.New("CRC error! Data On Disk Corrupted!")
+		}
+		return ret, e
+	}else if version == Version2 {
+	}
+	return 0, errors.New("Unsupported Version!")
+}
+func ReadNeedle(r *os.File) (*Needle, uint32) {
+	n := new(Needle)
+	bytes := make([]byte, 16)
+	count, e := r.Read(bytes)
+	if count <= 0 || e != nil {
+		return nil, 0
+	}
+	n.Cookie = util.BytesToUint32(bytes[0:4])
+	n.Id = util.BytesToUint64(bytes[4:12])
+	n.Size = util.BytesToUint32(bytes[12:16])
+	rest := 8 - ((n.Size + 16 + 4) % 8)
+	return n, n.Size + 4 + rest
+}
diff --git a/weed-fs/src/pkg/storage/volume.go b/weed-fs/src/pkg/storage/volume.go
index c1931d281..f5a810986 100644
--- a/weed-fs/src/pkg/storage/volume.go
+++ b/weed-fs/src/pkg/storage/volume.go
@@ -8,11 +8,8 @@ import (
 	"sync"
 )
 
-type Version uint8
-
 const (
 	SuperBlockSize = 8
-	CurrentVersion = Version(1)
 )
 
 type Volume struct {
diff --git a/weed-fs/src/pkg/storage/volume_version.go b/weed-fs/src/pkg/storage/volume_version.go
new file mode 100644
index 000000000..974a8079c
--- /dev/null
+++ b/weed-fs/src/pkg/storage/volume_version.go
@@ -0,0 +1,12 @@
+package storage
+
+import (
+)
+
+type Version uint8
+
+const (
+	CurrentVersion = Version(1)
+	Version1 = Version(1)
+    Version2 = Version(2)
+)