diff --git a/weed/server/master_server_handlers_admin.go b/weed/server/master_server_handlers_admin.go
index bbac62bcd..67c030042 100644
--- a/weed/server/master_server_handlers_admin.go
+++ b/weed/server/master_server_handlers_admin.go
@@ -11,6 +11,7 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/operation"
 	"github.com/chrislusf/seaweedfs/weed/pb/volume_server_pb"
 	"github.com/chrislusf/seaweedfs/weed/storage"
+	"github.com/chrislusf/seaweedfs/weed/storage/memory_map"
 	"github.com/chrislusf/seaweedfs/weed/storage/needle"
 	"github.com/chrislusf/seaweedfs/weed/topology"
 	"github.com/chrislusf/seaweedfs/weed/util"
@@ -147,7 +148,7 @@ func (ms *MasterServer) getVolumeGrowOption(r *http.Request) (*topology.VolumeGr
 	if err != nil {
 		return nil, err
 	}
-	memoryMapMaxSizeMb, err := needle.ReadMemoryMapMaxSizeMb(r.FormValue("memoryMapMaxSizeMb"))
+	memoryMapMaxSizeMb, err := memory_map.ReadMemoryMapMaxSizeMb(r.FormValue("memoryMapMaxSizeMb"))
 	if err != nil {
 		return nil, err
 	}
diff --git a/weed/storage/memory_map/memory_map.go b/weed/storage/memory_map/memory_map.go
index 5f0327ea7..e940fcc0e 100644
--- a/weed/storage/memory_map/memory_map.go
+++ b/weed/storage/memory_map/memory_map.go
@@ -1,10 +1,8 @@
-// +build !windows
-
 package memory_map
 
 import (
-	"fmt"
 	"os"
+	"strconv"
 )
 
 type MemoryBuffer struct {
@@ -25,18 +23,10 @@ type MemoryMap struct {
 
 var FileMemoryMap = make(map[string]*MemoryMap)
 
-func (mMap *MemoryMap) CreateMemoryMap(file *os.File, maxLength uint64) {
-}
-
-func (mMap *MemoryMap) WriteMemory(offset uint64, length uint64, data []byte) {
-
-}
-
-func (mMap *MemoryMap) ReadMemory(offset uint64, length uint64) ([]byte, error) {
-	dataSlice := []byte{}
-	return dataSlice, fmt.Errorf("Memory Map not implemented for this platform")
-}
-
-func (mBuffer *MemoryMap) DeleteFileAndMemoryMap() {
-
+func ReadMemoryMapMaxSizeMb(memoryMapMaxSizeMbString string) (uint32, error) {
+	if memoryMapMaxSizeMbString == "" {
+		return 0, nil
+	}
+	memoryMapMaxSize64, err := strconv.ParseUint(memoryMapMaxSizeMbString, 10, 32)
+	return uint32(memoryMapMaxSize64), err
 }
diff --git a/weed/storage/memory_map/memory_map_other.go b/weed/storage/memory_map/memory_map_other.go
new file mode 100644
index 000000000..e06a0b59a
--- /dev/null
+++ b/weed/storage/memory_map/memory_map_other.go
@@ -0,0 +1,24 @@
+// +build !windows
+
+package memory_map
+
+import (
+	"fmt"
+	"os"
+)
+
+func (mMap *MemoryMap) CreateMemoryMap(file *os.File, maxLength uint64) {
+}
+
+func (mMap *MemoryMap) WriteMemory(offset uint64, length uint64, data []byte) {
+
+}
+
+func (mMap *MemoryMap) ReadMemory(offset uint64, length uint64) ([]byte, error) {
+	dataSlice := []byte{}
+	return dataSlice, fmt.Errorf("Memory Map not implemented for this platform")
+}
+
+func (mBuffer *MemoryMap) DeleteFileAndMemoryMap() {
+
+}
diff --git a/weed/storage/needle/volume_memory_map_max_size_test.go b/weed/storage/memory_map/memory_map_test.go
similarity index 91%
rename from weed/storage/needle/volume_memory_map_max_size_test.go
rename to weed/storage/memory_map/memory_map_test.go
index 64d693d17..33e1a828c 100644
--- a/weed/storage/needle/volume_memory_map_max_size_test.go
+++ b/weed/storage/memory_map/memory_map_test.go
@@ -1,4 +1,4 @@
-package needle
+package memory_map
 
 import "testing"
 
diff --git a/weed/storage/memory_map/memory_map_windows.go b/weed/storage/memory_map/memory_map_windows.go
index ac4493188..7eb713442 100644
--- a/weed/storage/memory_map/memory_map_windows.go
+++ b/weed/storage/memory_map/memory_map_windows.go
@@ -11,24 +11,6 @@ import (
 	"golang.org/x/sys/windows"
 )
 
-type MemoryBuffer struct {
-	aligned_length uint64
-	length         uint64
-	aligned_ptr    uintptr
-	ptr            uintptr
-	Buffer         []byte
-}
-
-type MemoryMap struct {
-	File                   *os.File
-	file_memory_map_handle uintptr
-	write_map_views        []MemoryBuffer
-	max_length             uint64
-	End_of_file            int64
-}
-
-var FileMemoryMap = make(map[string]*MemoryMap)
-
 type DWORDLONG = uint64
 type DWORD = uint32
 type WORD = uint16
diff --git a/weed/storage/needle/volume_memory_map_max_size.go b/weed/storage/needle/volume_memory_map_max_size.go
deleted file mode 100644
index ca7b03b48..000000000
--- a/weed/storage/needle/volume_memory_map_max_size.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package needle
-
-import "strconv"
-
-func ReadMemoryMapMaxSizeMb(MemoryMapMaxSizeMbString string) (uint32, error) {
-	if MemoryMapMaxSizeMbString == "" {
-		return 0, nil
-	}
-	var MemoryMapMaxSize64 uint64
-	var err error
-	MemoryMapMaxSize64, err = strconv.ParseUint(MemoryMapMaxSizeMbString, 10, 32)
-	MemoryMapMaxSize := uint32(MemoryMapMaxSize64)
-	return MemoryMapMaxSize, err
-}