diff --git a/weed/util/bytes.go b/weed/util/bytes.go
index d9e462693..d72d199f8 100644
--- a/weed/util/bytes.go
+++ b/weed/util/bytes.go
@@ -2,6 +2,7 @@ package util
 
 import (
 	"crypto/md5"
+	"fmt"
 	"io"
 )
 
@@ -91,3 +92,9 @@ func HashToInt32(data []byte) (v int32) {
 
 	return
 }
+
+func Md5(data []byte) string {
+	hash := md5.New()
+	hash.Write(data)
+	return fmt.Sprintf("%x", hash.Sum(nil))
+}