diff --git a/weed/topology/topology_event_handling.go b/weed/topology/topology_event_handling.go
index 4d9d4cbe5..a301103eb 100644
--- a/weed/topology/topology_event_handling.go
+++ b/weed/topology/topology_event_handling.go
@@ -40,6 +40,10 @@ func (t *Topology) SetVolumeCapacityFull(volumeInfo storage.VolumeInfo) bool {
 	if !vl.SetVolumeCapacityFull(volumeInfo.Id) {
 		return false
 	}
+
+	vl.accessLock.RLock()
+	defer vl.accessLock.RUnlock()
+
 	for _, dn := range vl.vid2location[volumeInfo.Id].list {
 		if !volumeInfo.ReadOnly {
 			dn.UpAdjustActiveVolumeCountDelta(-1)
diff --git a/weed/topology/topology_vacuum.go b/weed/topology/topology_vacuum.go
index 29b3c339b..c270ef9d4 100644
--- a/weed/topology/topology_vacuum.go
+++ b/weed/topology/topology_vacuum.go
@@ -122,29 +122,41 @@ func (t *Topology) Vacuum(garbageThreshold float64, preallocate int64) int {
 		for _, vl := range c.storageType2VolumeLayout.Items() {
 			if vl != nil {
 				volumeLayout := vl.(*VolumeLayout)
-				for vid, locationlist := range volumeLayout.vid2location {
-
-					volumeLayout.accessLock.RLock()
-					isReadOnly, hasValue := volumeLayout.readonlyVolumes[vid]
-					volumeLayout.accessLock.RUnlock()
-
-					if hasValue && isReadOnly {
-						continue
-					}
-
-					glog.V(0).Infof("check vacuum on collection:%s volume:%d", c.Name, vid)
-					if batchVacuumVolumeCheck(volumeLayout, vid, locationlist, garbageThreshold) {
-						if batchVacuumVolumeCompact(volumeLayout, vid, locationlist, preallocate) {
-							batchVacuumVolumeCommit(volumeLayout, vid, locationlist)
-						}
-					}
-				}
+				vacuumOneVolumeLayout(volumeLayout, c, garbageThreshold, preallocate)
 			}
 		}
 	}
 	return 0
 }
 
+func vacuumOneVolumeLayout(volumeLayout *VolumeLayout, c *Collection, garbageThreshold float64, preallocate int64) {
+
+	volumeLayout.accessLock.RLock()
+	tmpMap := make(map[storage.VolumeId]*VolumeLocationList)
+	for vid, locationlist := range volumeLayout.vid2location {
+		tmpMap[vid] = locationlist
+	}
+	volumeLayout.accessLock.RUnlock()
+
+	for vid, locationlist := range tmpMap {
+
+		volumeLayout.accessLock.RLock()
+		isReadOnly, hasValue := volumeLayout.readonlyVolumes[vid]
+		volumeLayout.accessLock.RUnlock()
+
+		if hasValue && isReadOnly {
+			continue
+		}
+
+		glog.V(0).Infof("check vacuum on collection:%s volume:%d", c.Name, vid)
+		if batchVacuumVolumeCheck(volumeLayout, vid, locationlist, garbageThreshold) {
+			if batchVacuumVolumeCompact(volumeLayout, vid, locationlist, preallocate) {
+				batchVacuumVolumeCommit(volumeLayout, vid, locationlist)
+			}
+		}
+	}
+}
+
 type VacuumVolumeResult struct {
 	Result bool
 	Error  string