diff --git a/weed-fs/src/cmd/weed/volume.go b/weed-fs/src/cmd/weed/volume.go
index 6537cea13..b65433e81 100644
--- a/weed-fs/src/cmd/weed/volume.go
+++ b/weed-fs/src/cmd/weed/volume.go
@@ -57,6 +57,15 @@ func assignVolumeHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	debug("assign volume =", r.FormValue("volume"), ", replicationType =", r.FormValue("replicationType"), ", error =", err)
 }
+func vacuumVolumeCheckHandler(w http.ResponseWriter, r *http.Request) {
+    err, ret := store.CheckCompactVolume(r.FormValue("volume"), r.FormValue("garbageThreshold"))
+    if err == nil {
+        writeJson(w, r, map[string]interface{}{"error": "", "result": ret})
+    } else {
+        writeJson(w, r, map[string]interface{}{"error": err.Error(), "result": false})
+    }
+    debug("checked compacting volume =", r.FormValue("volume"), "garbageThreshold =", r.FormValue("garbageThreshold"), "vacuum =", ret)
+}
 func vacuumVolumeCompactHandler(w http.ResponseWriter, r *http.Request) {
 	err := store.CompactVolume(r.FormValue("volume"))
 	if err == nil {
@@ -67,9 +76,9 @@ func vacuumVolumeCompactHandler(w http.ResponseWriter, r *http.Request) {
 	debug("compacted volume =", r.FormValue("volume"), ", error =", err)
 }
 func vacuumVolumeCommitHandler(w http.ResponseWriter, r *http.Request) {
-	count, err := store.CommitCompactVolume(r.FormValue("volume"))
+	err := store.CommitCompactVolume(r.FormValue("volume"))
 	if err == nil {
-		writeJson(w, r, map[string]interface{}{"error": "", "size": count})
+		writeJson(w, r, map[string]interface{}{"error": ""})
 	} else {
 		writeJson(w, r, map[string]string{"error": err.Error()})
 	}
@@ -302,6 +311,7 @@ func runVolume(cmd *Command, args []string) bool {
 	http.HandleFunc("/", storeHandler)
 	http.HandleFunc("/status", statusHandler)
 	http.HandleFunc("/admin/assign_volume", assignVolumeHandler)
+    http.HandleFunc("/admin/vacuum_volume_check", vacuumVolumeCheckHandler)
 	http.HandleFunc("/admin/vacuum_volume_compact", vacuumVolumeCompactHandler)
 	http.HandleFunc("/admin/vacuum_volume_commit", vacuumVolumeCommitHandler)
 
diff --git a/weed-fs/src/pkg/storage/compact_map.go b/weed-fs/src/pkg/storage/compact_map.go
index 4e83a76c8..7365022ea 100644
--- a/weed-fs/src/pkg/storage/compact_map.go
+++ b/weed-fs/src/pkg/storage/compact_map.go
@@ -29,17 +29,25 @@ func NewCompactSection(start Key) CompactSection {
 		start:    start,
 	}
 }
-func (cs *CompactSection) Set(key Key, offset uint32, size uint32) {
+
+//return old entry size
+func (cs *CompactSection) Set(key Key, offset uint32, size uint32) uint32 {
+	ret := uint32(0)
 	if key > cs.end {
 		cs.end = key
 	}
 	if i := cs.binarySearchValues(key); i >= 0 {
+		ret = cs.values[i].Size
+		//println("key", key, "old size", ret)
 		cs.values[i].Offset, cs.values[i].Size = offset, size
 	} else {
-	  needOverflow := cs.counter >= batch
-	  needOverflow = needOverflow || cs.counter > 0 && cs.values[cs.counter-1].Key > key
+		needOverflow := cs.counter >= batch
+		needOverflow = needOverflow || cs.counter > 0 && cs.values[cs.counter-1].Key > key
 		if needOverflow {
 			//println("start", cs.start, "counter", cs.counter, "key", key)
+			if oldValue := cs.overflow[key]; oldValue != nil {
+				ret = oldValue.Size
+			}
 			cs.overflow[key] = &NeedleValue{Key: key, Offset: offset, Size: size}
 		} else {
 			p := &cs.values[cs.counter]
@@ -48,12 +56,23 @@ func (cs *CompactSection) Set(key Key, offset uint32, size uint32) {
 			cs.counter++
 		}
 	}
+	return ret
 }
-func (cs *CompactSection) Delete(key Key) {
+
+//return old entry size
+func (cs *CompactSection) Delete(key Key) uint32 {
+	ret := uint32(0)
 	if i := cs.binarySearchValues(key); i >= 0 {
-		cs.values[i].Size = 0
+		if cs.values[i].Size > 0 {
+			ret = cs.values[i].Size
+			cs.values[i].Size = 0
+		}
 	}
-	delete(cs.overflow, key)
+	if v := cs.overflow[key]; v != nil {
+		delete(cs.overflow, key)
+		ret = v.Size
+	}
+	return ret
 }
 func (cs *CompactSection) Get(key Key) (*NeedleValue, bool) {
 	if v, ok := cs.overflow[key]; ok {
@@ -94,21 +113,21 @@ func NewCompactMap() CompactMap {
 	return CompactMap{}
 }
 
-func (cm *CompactMap) Set(key Key, offset uint32, size uint32) {
+func (cm *CompactMap) Set(key Key, offset uint32, size uint32) uint32 {
 	x := cm.binarySearchCompactSection(key)
 	if x < 0 {
 		//println(x, "creating", len(cm.list), "section1, starting", key)
 		cm.list = append(cm.list, NewCompactSection(key))
 		x = len(cm.list) - 1
 	}
-	cm.list[x].Set(key, offset, size)
+	return cm.list[x].Set(key, offset, size)
 }
-func (cm *CompactMap) Delete(key Key) {
+func (cm *CompactMap) Delete(key Key) uint32 {
 	x := cm.binarySearchCompactSection(key)
 	if x < 0 {
-		return
+		return uint32(0)
 	}
-	cm.list[x].Delete(key)
+	return cm.list[x].Delete(key)
 }
 func (cm *CompactMap) Get(key Key) (*NeedleValue, bool) {
 	x := cm.binarySearchCompactSection(key)
@@ -123,7 +142,7 @@ func (cm *CompactMap) binarySearchCompactSection(key Key) int {
 		return -5
 	}
 	if cm.list[h].start <= key {
-		if cm.list[h].counter < batch || key <= cm.list[h].end{
+		if cm.list[h].counter < batch || key <= cm.list[h].end {
 			return h
 		} else {
 			return -4
@@ -150,9 +169,9 @@ func (cm *CompactMap) Peek() {
 			println("[", v.Key, v.Offset, v.Size, "]")
 		}
 	}
-  for k, v := range cm.list[0].overflow {
-    if k < 100 {
-      println("o[", v.Key, v.Offset, v.Size, "]")
-    }
-  }
+	for k, v := range cm.list[0].overflow {
+		if k < 100 {
+			println("o[", v.Key, v.Offset, v.Size, "]")
+		}
+	}
 }
diff --git a/weed-fs/src/pkg/storage/needle_map.go b/weed-fs/src/pkg/storage/needle_map.go
index c5dca524d..ac6998337 100644
--- a/weed-fs/src/pkg/storage/needle_map.go
+++ b/weed-fs/src/pkg/storage/needle_map.go
@@ -11,9 +11,11 @@ type NeedleMap struct {
 	m         CompactMap
 
 	//transient
-	bytes           []byte
-	deletionCounter int
-	fileCounter     int
+	bytes []byte
+
+	deletionCounter     int
+	fileCounter         int
+	deletionByteCounter uint32
 }
 
 func NewNeedleMap(file *os.File) *NeedleMap {
@@ -43,13 +45,18 @@ func LoadNeedleMap(file *os.File) *NeedleMap {
 			offset := util.BytesToUint32(bytes[i+8 : i+12])
 			size := util.BytesToUint32(bytes[i+12 : i+16])
 			if offset > 0 {
-				nm.m.Set(Key(key), offset, size)
-				//log.Println("reading key", key, "offset", offset, "size", size)
+				oldSize := nm.m.Set(Key(key), offset, size)
+				//log.Println("reading key", key, "offset", offset, "size", size, "oldSize", oldSize)
 				nm.fileCounter++
+				if oldSize > 0 {
+					nm.deletionCounter++
+					nm.deletionByteCounter = nm.deletionByteCounter + oldSize
+				}
 			} else {
 				nm.m.Delete(Key(key))
-        //log.Println("removing key", key)
+				//log.Println("removing key", key)
 				nm.deletionCounter++
+				nm.deletionByteCounter = nm.deletionByteCounter + size
 			}
 		}
 
@@ -59,11 +66,15 @@ func LoadNeedleMap(file *os.File) *NeedleMap {
 }
 
 func (nm *NeedleMap) Put(key uint64, offset uint32, size uint32) (int, error) {
-	nm.m.Set(Key(key), offset, size)
+	oldSize := nm.m.Set(Key(key), offset, size)
 	util.Uint64toBytes(nm.bytes[0:8], key)
 	util.Uint32toBytes(nm.bytes[8:12], offset)
 	util.Uint32toBytes(nm.bytes[12:16], size)
 	nm.fileCounter++
+	if oldSize > 0 {
+		nm.deletionCounter++
+		nm.deletionByteCounter = nm.deletionByteCounter + oldSize
+	}
 	return nm.indexFile.Write(nm.bytes)
 }
 func (nm *NeedleMap) Get(key uint64) (element *NeedleValue, ok bool) {
@@ -71,7 +82,7 @@ func (nm *NeedleMap) Get(key uint64) (element *NeedleValue, ok bool) {
 	return
 }
 func (nm *NeedleMap) Delete(key uint64) {
-	nm.m.Delete(Key(key))
+	nm.deletionByteCounter = nm.deletionByteCounter + nm.m.Delete(Key(key))
 	util.Uint64toBytes(nm.bytes[0:8], key)
 	util.Uint32toBytes(nm.bytes[8:12], 0)
 	util.Uint32toBytes(nm.bytes[12:16], 0)
diff --git a/weed-fs/src/pkg/storage/store.go b/weed-fs/src/pkg/storage/store.go
index fb49e9059..03d4357e4 100644
--- a/weed-fs/src/pkg/storage/store.go
+++ b/weed-fs/src/pkg/storage/store.go
@@ -69,6 +69,17 @@ func (s *Store) addVolume(vid VolumeId, replicationType ReplicationType) error {
 	return nil
 }
 
+func (s *Store) CheckCompactVolume(volumeIdString string, garbageThresholdString string) (error, bool) {
+    vid, err := NewVolumeId(volumeIdString)
+    if err != nil {
+        return errors.New("Volume Id " + volumeIdString + " is not a valid unsigned integer!"), false
+    }
+    garbageThreshold, e := strconv.ParseFloat(garbageThresholdString, 32)
+    if e != nil {
+        return errors.New("garbageThreshold " + garbageThresholdString + " is not a valid float number!"), false
+    }
+    return nil, garbageThreshold < s.volumes[vid].garbageLevel()
+}
 func (s *Store) CompactVolume(volumeIdString string) error {
 	vid, err := NewVolumeId(volumeIdString)
 	if err != nil {
@@ -76,10 +87,10 @@ func (s *Store) CompactVolume(volumeIdString string) error {
 	}
 	return s.volumes[vid].compact()
 }
-func (s *Store) CommitCompactVolume(volumeIdString string) (int,error) {
+func (s *Store) CommitCompactVolume(volumeIdString string) (error) {
   vid, err := NewVolumeId(volumeIdString)
   if err != nil {
-    return 0, errors.New("Volume Id " + volumeIdString + " is not a valid unsigned integer!")
+    return errors.New("Volume Id " + volumeIdString + " is not a valid unsigned integer!")
   }
   return s.volumes[vid].commitCompact()
 }
@@ -104,7 +115,7 @@ func (s *Store) Status() []*VolumeInfo {
 	var stats []*VolumeInfo
 	for k, v := range s.volumes {
 		s := new(VolumeInfo)
-		s.Id, s.Size, s.RepType, s.FileCount, s.DeleteCount = VolumeId(k), v.Size(), v.replicaType, v.nm.fileCounter, v.nm.deletionCounter
+		s.Id, s.Size, s.RepType, s.FileCount, s.DeleteCount, s.DeletedByteCount = VolumeId(k), v.Size(), v.replicaType, v.nm.fileCounter, v.nm.deletionCounter, v.nm.deletionByteCounter
 		stats = append(stats, s)
 	}
 	return stats
@@ -113,7 +124,7 @@ func (s *Store) Join(mserver string) error {
 	stats := new([]*VolumeInfo)
 	for k, v := range s.volumes {
 		s := new(VolumeInfo)
-		s.Id, s.Size, s.RepType, s.FileCount, s.DeleteCount = VolumeId(k), v.Size(), v.replicaType, v.nm.fileCounter, v.nm.deletionCounter
+		s.Id, s.Size, s.RepType, s.FileCount, s.DeleteCount, s.DeletedByteCount = VolumeId(k), v.Size(), v.replicaType, v.nm.fileCounter, v.nm.deletionCounter, v.nm.deletionByteCounter
 		*stats = append(*stats, s)
 	}
 	bytes, _ := json.Marshal(stats)
diff --git a/weed-fs/src/pkg/storage/volume.go b/weed-fs/src/pkg/storage/volume.go
index 4ada4e734..8c8a4ea88 100644
--- a/weed-fs/src/pkg/storage/volume.go
+++ b/weed-fs/src/pkg/storage/volume.go
@@ -55,13 +55,18 @@ func (v *Volume) load() error {
 	return nil
 }
 func (v *Volume) Size() int64 {
+    v.accessLock.Lock()
+    defer v.accessLock.Unlock()
 	stat, e := v.dataFile.Stat()
 	if e == nil {
 		return stat.Size()
 	}
+	fmt.Printf("Failed to read file size %s %s\n", v.dataFile.Name(), e.Error())
 	return -1
 }
 func (v *Volume) Close() {
+    v.accessLock.Lock()
+    defer v.accessLock.Unlock()
 	v.nm.Close()
 	v.dataFile.Close()
 }
@@ -115,6 +120,7 @@ func (v *Volume) delete(n *Needle) uint32 {
 	}
 	return 0
 }
+
 func (v *Volume) read(n *Needle) (int, error) {
 	v.accessLock.Lock()
 	defer v.accessLock.Unlock()
@@ -126,6 +132,10 @@ func (v *Volume) read(n *Needle) (int, error) {
 	return -1, errors.New("Not Found")
 }
 
+func (v *Volume) garbageLevel() float64 {
+    return float64(v.nm.deletionByteCounter)/float64(v.Size())
+}
+
 func (v *Volume) compact() error {
 	v.accessLock.Lock()
 	defer v.accessLock.Unlock()
@@ -133,21 +143,21 @@ func (v *Volume) compact() error {
 	filePath := path.Join(v.dir, v.Id.String())
 	return v.copyDataAndGenerateIndexFile(filePath+".dat", filePath+".cpd", filePath+".cpx")
 }
-func (v *Volume) commitCompact() (int, error) {
+func (v *Volume) commitCompact() (error) {
 	v.accessLock.Lock()
 	defer v.accessLock.Unlock()
 	v.dataFile.Close()
 	var e error
 	if e = os.Rename(path.Join(v.dir, v.Id.String()+".cpd"), path.Join(v.dir, v.Id.String()+".dat")); e != nil {
-		return 0, e
+		return e
 	}
 	if e = os.Rename(path.Join(v.dir, v.Id.String()+".cpx"), path.Join(v.dir, v.Id.String()+".idx")); e != nil {
-		return 0, e
+		return e
 	}
 	if e = v.load(); e != nil {
-		return 0, e
+		return e
 	}
-	return 0, nil
+	return nil
 }
 
 func (v *Volume) copyDataAndGenerateIndexFile(srcName, dstName, idxName string) (err error) {
@@ -183,7 +193,6 @@ func (v *Volume) copyDataAndGenerateIndexFile(srcName, dstName, idxName string)
 		nv, ok := v.nm.Get(n.Id)
 		//log.Println("file size is", n.Size, "rest", rest)
 		if !ok || nv.Offset*8 != old_offset {
-			log.Println("expected offset should be", nv.Offset*8, "skipping", (rest - 16), "key", n.Id, "volume offset", old_offset, "data_size", n.Size, "rest", rest)
 			src.Seek(int64(rest), 1)
 		} else {
 			if nv.Size > 0 {
diff --git a/weed-fs/src/pkg/storage/volume_info.go b/weed-fs/src/pkg/storage/volume_info.go
index 05b9e6205..dfedb0af3 100644
--- a/weed-fs/src/pkg/storage/volume_info.go
+++ b/weed-fs/src/pkg/storage/volume_info.go
@@ -9,4 +9,5 @@ type VolumeInfo struct {
 	RepType ReplicationType
 	FileCount int
 	DeleteCount int
+    DeletedByteCount uint32
 }
diff --git a/weed-fs/src/pkg/topology/node.go b/weed-fs/src/pkg/topology/node.go
index c3184b3da..81bad7da5 100644
--- a/weed-fs/src/pkg/topology/node.go
+++ b/weed-fs/src/pkg/topology/node.go
@@ -164,6 +164,7 @@ func (n *NodeImpl) CollectDeadNodeAndFullVolumes(freshThreshHold int64, volumeSi
 			}
 			for _, v := range dn.volumes {
 				if uint64(v.Size) >= volumeSizeLimit {
+				    //fmt.Println("volume",v.Id,"size",v.Size,">",volumeSizeLimit)
 					n.GetTopology().chanFullVolumes <- &v
 				}
 			}
diff --git a/weed-fs/src/pkg/topology/topology_compact.go b/weed-fs/src/pkg/topology/topology_compact.go
index e6232cec6..c8ad9b2e7 100644
--- a/weed-fs/src/pkg/topology/topology_compact.go
+++ b/weed-fs/src/pkg/topology/topology_compact.go
@@ -3,45 +3,90 @@ package topology
 import (
 	"encoding/json"
 	"errors"
-  "fmt"
+	"fmt"
 	"net/url"
 	"pkg/storage"
 	"pkg/util"
 	"time"
 )
 
+func batchVacuumVolumeCheck(vl *VolumeLayout, vid storage.VolumeId, locationlist *VolumeLocationList) bool {
+	ch := make(chan bool, locationlist.Length())
+	for index, dn := range locationlist.list {
+		go func(index int, url string, vid storage.VolumeId) {
+			//fmt.Println(index, "Check vacuuming", vid, "on", dn.Url())
+			if e, ret := vacuumVolume_Check(url, vid); e != nil {
+				//fmt.Println(index, "Error when checking vacuuming", vid, "on", url, e)
+				ch <- false
+			} else {
+				//fmt.Println(index, "Checked vacuuming", vid, "on", url)
+				ch <- ret
+			}
+		}(index, dn.Url(), vid)
+	}
+	isCheckSuccess := true
+	for _ = range locationlist.list {
+		select {
+		case canVacuum := <-ch:
+			isCheckSuccess = isCheckSuccess && canVacuum
+		case <-time.After(30 * time.Minute):
+			isCheckSuccess = false
+			break
+		}
+	}
+	return isCheckSuccess
+}
+func batchVacuumVolumeCompact(vl *VolumeLayout, vid storage.VolumeId, locationlist *VolumeLocationList) bool {
+	vl.removeFromWritable(vid)
+	ch := make(chan bool, locationlist.Length())
+	for index, dn := range locationlist.list {
+		go func(index int, url string, vid storage.VolumeId) {
+			fmt.Println(index, "Start vacuuming", vid, "on", dn.Url())
+			if e := vacuumVolume_Compact(url, vid); e != nil {
+				fmt.Println(index, "Error when vacuuming", vid, "on", url, e)
+				ch <- false
+			} else {
+				fmt.Println(index, "Complete vacuuming", vid, "on", url)
+				ch <- true
+			}
+		}(index, dn.Url(), vid)
+	}
+	isVacuumSuccess := true
+	for _ = range locationlist.list {
+		select {
+		case _ = <-ch:
+		case <-time.After(30 * time.Minute):
+			isVacuumSuccess = false
+			break
+		}
+	}
+	return isVacuumSuccess
+}
+func batchVacuumVolumeCommit(vl *VolumeLayout, vid storage.VolumeId, locationlist *VolumeLocationList) bool {
+	isCommitSuccess := true
+	for _, dn := range locationlist.list {
+		fmt.Println("Start Commiting vacuum", vid, "on", dn.Url())
+		if e := vacuumVolume_Commit(dn.Url(), vid); e != nil {
+			fmt.Println("Error when committing vacuum", vid, "on", dn.Url(), e)
+			isCommitSuccess = false
+		} else {
+			fmt.Println("Complete Commiting vacuum", vid, "on", dn.Url())
+		}
+	}
+	if isCommitSuccess {
+		vl.setVolumeWritable(vid)
+	}
+	return isCommitSuccess
+}
 func (t *Topology) Vacuum() int {
-	total_counter := 0
 	for _, vl := range t.replicaType2VolumeLayout {
 		if vl != nil {
 			for vid, locationlist := range vl.vid2location {
-				each_volume_counter := 0
-				vl.removeFromWritable(vid)
-				ch := make(chan int, locationlist.Length())
-				for _, dn := range locationlist.list {
-					go func(url string, vid storage.VolumeId) {
-						vacuumVolume_Compact(url, vid)
-					}(dn.Url(), vid)
-				}
-				for _ = range locationlist.list {
-					select {
-					case count := <-ch:
-						each_volume_counter += count
-					case <-time.After(30 * time.Minute):
-						each_volume_counter = 0
-						break
+				if batchVacuumVolumeCheck(vl, vid, locationlist) {
+					if batchVacuumVolumeCompact(vl, vid, locationlist) {
+						batchVacuumVolumeCommit(vl, vid, locationlist)
 					}
 				}
-				if each_volume_counter > 0 {
-					for _, dn := range locationlist.list {
-						if e := vacuumVolume_Commit(dn.Url(), vid); e != nil {
-							fmt.Println("Error when committing on", dn.Url(), e)
-							panic(e)
-						}
-					}
-					vl.setVolumeWritable(vid)
-					total_counter += each_volume_counter
-				}
 			}
 		}
 	}
@@ -49,25 +94,42 @@ func (t *Topology) Vacuum() int {
 }
 
 type VacuumVolumeResult struct {
-	Bytes int
-	Error string
+	Result bool
+	Error  string
 }
 
-func vacuumVolume_Compact(urlLocation string, vid storage.VolumeId) (error, int) {
+func vacuumVolume_Check(urlLocation string, vid storage.VolumeId) (error, bool) {
+	values := make(url.Values)
+	values.Add("volume", vid.String())
+    values.Add("garbageThreshold", "0.3")
+	jsonBlob, err := util.Post("http://"+urlLocation+"/admin/vacuum_volume_check", values)
+	if err != nil {
+		return err, false
+	}
+	var ret VacuumVolumeResult
+	if err := json.Unmarshal(jsonBlob, &ret); err != nil {
+		return err, false
+	}
+	if ret.Error != "" {
+		return errors.New(ret.Error), false
+	}
+	return nil, ret.Result
+}
+func vacuumVolume_Compact(urlLocation string, vid storage.VolumeId) error {
 	values := make(url.Values)
 	values.Add("volume", vid.String())
 	jsonBlob, err := util.Post("http://"+urlLocation+"/admin/vacuum_volume_compact", values)
 	if err != nil {
-		return err, 0
+		return err
 	}
 	var ret VacuumVolumeResult
 	if err := json.Unmarshal(jsonBlob, &ret); err != nil {
-		return err, 0
+		return err
 	}
 	if ret.Error != "" {
-		return errors.New(ret.Error), 0
+		return errors.New(ret.Error)
 	}
-	return nil, ret.Bytes
+	return nil
 }
 func vacuumVolume_Commit(urlLocation string, vid storage.VolumeId) error {
 	values := make(url.Values)
diff --git a/weed-fs/src/pkg/topology/topology_event_handling.go b/weed-fs/src/pkg/topology/topology_event_handling.go
index 230ea1071..322d6c27a 100644
--- a/weed-fs/src/pkg/topology/topology_event_handling.go
+++ b/weed-fs/src/pkg/topology/topology_event_handling.go
@@ -15,6 +15,12 @@ func (t *Topology) StartRefreshWritableVolumes() {
 			time.Sleep(time.Duration(float32(t.pulse*1e3)*(1+rand.Float32())) * time.Millisecond)
 		}
 	}()
+	go func() {
+		c := time.Tick(15 * time.Minute)
+		for _ = range c {
+			t.Vacuum()
+		}
+	}()
 	go func() {
 		for {
 			select {