diff --git a/weed-fs/src/cmd/weeds.go b/weed-fs/src/cmd/weeds.go
index c639d48d3..ba134380c 100644
--- a/weed-fs/src/cmd/weeds.go
+++ b/weed-fs/src/cmd/weeds.go
@@ -20,7 +20,7 @@ var (
 )
 
 func dirReadHandler(w http.ResponseWriter, r *http.Request) {
-	volumeId, _ := strconv.Atoi(r.FormValue("volumeId"))
+	volumeId, _ := strconv.Atoui64(r.FormValue("volumeId"))
 	machine := mapper.Get(volumeId)
 	writeJson(w, r, machine)
 }
@@ -55,7 +55,7 @@ func writeJson(w http.ResponseWriter, r *http.Request, obj interface{}) {
 		fmt.Fprint(w, string(bytes))
 		w.Write([]uint8(")"))
 	}
-	log.Println("JSON Response", string(bytes))
+	//log.Println("JSON Response", string(bytes))
 }
 
 func main() {
diff --git a/weed-fs/src/pkg/directory/volume_mapping.go b/weed-fs/src/pkg/directory/volume_mapping.go
index 4062b3109..b24b1747e 100644
--- a/weed-fs/src/pkg/directory/volume_mapping.go
+++ b/weed-fs/src/pkg/directory/volume_mapping.go
@@ -14,7 +14,12 @@ const (
 	ChunkSizeLimit = 1 * 1024 * 1024 * 1024 //1G, can not be more than max(uint32)*8
 )
 
+type MachineInfo struct {
+    Server       string //<server name/ip>[:port]
+    PublicServer string
+}
 type Machine struct {
+    MachineInfo
 	Server       string //<server name/ip>[:port]
 	PublicServer string
 	Volumes      []storage.VolumeInfo
@@ -29,7 +34,7 @@ type Mapper struct {
 	lock          sync.Mutex
 	Machines      []*Machine
 	vid2machineId map[uint64]int
-	writers       []int // transient array of writers volume id
+	Writers       []int // transient array of Writers volume id
 
 	GlobalVolumeSequence uint64
 }
@@ -46,7 +51,7 @@ func NewMapper(dirname string, filename string, capacity int) (m *Mapper) {
 	log.Println("Loading volume id to maching mapping:", path.Join(m.dir, m.fileName+".map"))
 	dataFile, e := os.OpenFile(path.Join(m.dir, m.fileName+".map"), os.O_RDONLY, 0644)
     m.vid2machineId = make(map[uint64]int)
-    m.writers = *new([]int)
+    m.Writers = *new([]int)
 	if e != nil {
 		log.Println("Mapping File Read", e)
 		m.Machines = *new([]*Machine)
@@ -56,12 +61,12 @@ func NewMapper(dirname string, filename string, capacity int) (m *Mapper) {
 		decoder.Decode(&m.Machines)
 		decoder.Decode(&m.GlobalVolumeSequence)
 
-		//add to vid2machineId map, and writers array
+		//add to vid2machineId map, and Writers array
 		for machine_index, machine := range m.Machines {
 			for _, v := range machine.Volumes {
 		        m.vid2machineId[v.Id] = machine_index
 				if v.Size < ChunkSizeLimit {
-					m.writers = append(m.writers, machine_index)
+					m.Writers = append(m.Writers, machine_index)
 				}
 			}
 		}
@@ -69,12 +74,15 @@ func NewMapper(dirname string, filename string, capacity int) (m *Mapper) {
 	}
 	return
 }
-func (m *Mapper) PickForWrite() *Machine {
-	vid := rand.Intn(len(m.writers))
-	return m.Machines[m.writers[vid]]
+func (m *Mapper) PickForWrite() map[string]string {
+	vid := rand.Intn(len(m.Writers))
+	return map[string]string{
+	  "server":m.Machines[m.Writers[vid]].Server,
+      "url":m.Machines[m.Writers[vid]].PublicServer,
+	}
 }
-func (m *Mapper) Get(vid int) *Machine {
-	return m.Machines[vid]
+func (m *Mapper) Get(vid uint64) *Machine {
+	return m.Machines[m.vid2machineId[vid]]
 }
 func (m *Mapper) Add(machine Machine) []uint64 {
 	log.Println("Adding existing", machine.Server, len(machine.Volumes), "volumes to dir", len(m.Machines))
@@ -109,26 +117,26 @@ func (m *Mapper) Add(machine Machine) []uint64 {
 	m.Save()
 	m.lock.Unlock()
 
-	//add to vid2machineId map, and writers array
+	//add to vid2machineId map, and Writers array
 	for _, v := range machine.Volumes {
 		log.Println("Setting volume", v.Id, "to", machine.Server)
 		m.vid2machineId[v.Id] = machineId
 		if v.Size < ChunkSizeLimit {
-			m.writers = append(m.writers, machineId)
+			m.Writers = append(m.Writers, machineId)
 		}
 	}
-	//setting writers, copy-on-write because of possible updating
-	var writers []int
+	//setting Writers, copy-on-write because of possible updating
+	var Writers []int
     for machine_index, machine_entry := range m.Machines {
         for _, v := range machine_entry.Volumes {
             if v.Size < ChunkSizeLimit {
-                writers = append(writers, machine_index)
+                Writers = append(Writers, machine_index)
             }
         }
     }
-    m.writers = writers
+    m.Writers = Writers
 
-	log.Println("Machines:", len(m.Machines), "Volumes:", len(m.vid2machineId), "Writable:", len(m.writers))
+	log.Println("Machines:", len(m.Machines), "Volumes:", len(m.vid2machineId), "Writable:", len(m.Writers))
 	return *vids
 }
 func (m *Mapper) Save() {