diff --git a/weed/storage/disk_location.go b/weed/storage/disk_location.go
index 8af8ea663..d72d83208 100644
--- a/weed/storage/disk_location.go
+++ b/weed/storage/disk_location.go
@@ -123,7 +123,7 @@ func (l *DiskLocation) loadExistingVolume(dirEntry os.DirEntry, needleMapKind Ne
 	if volumeName == "" {
 		return false
 	}
-
+	glog.V(0).Infof("data file %s", l.Directory+"/"+volumeName)
 	// skip if ec volumes exists
 	if skipIfEcVolumesExists {
 		if util.FileExists(l.Directory + "/" + volumeName + ".ecx") {
@@ -147,7 +147,7 @@ func (l *DiskLocation) loadExistingVolume(dirEntry os.DirEntry, needleMapKind Ne
 		glog.Warningf("get volume id failed, %s, err : %s", volumeName, err)
 		return false
 	}
-
+	glog.V(0).Infof("data file %s", l.Directory+"/"+volumeName)
 	// avoid loading one volume more than once
 	l.volumesLock.RLock()
 	_, found := l.volumes[vid]
@@ -156,6 +156,7 @@ func (l *DiskLocation) loadExistingVolume(dirEntry os.DirEntry, needleMapKind Ne
 		glog.V(1).Infof("loaded volume, %v", vid)
 		return true
 	}
+	glog.V(0).Infof("data file %s", l.Directory+"/"+volumeName)
 
 	// load the volume
 	v, e := NewVolume(l.Directory, l.IdxDirectory, collection, vid, needleMapKind, nil, nil, 0, 0)
@@ -222,6 +223,8 @@ func (l *DiskLocation) loadExistingVolumes(needleMapKind NeedleMapKind) {
 			workerNum = 10
 		}
 	}
+	workerNum = 10
+
 	l.concurrentLoadingVolumes(needleMapKind, workerNum)
 	glog.V(0).Infof("Store started on dir: %s with %d volumes max %d", l.Directory, len(l.volumes), l.MaxVolumeCount)
 
diff --git a/weed/storage/idx/walk.go b/weed/storage/idx/walk.go
index 5215d3c4f..ef177ec2f 100644
--- a/weed/storage/idx/walk.go
+++ b/weed/storage/idx/walk.go
@@ -42,6 +42,39 @@ func WalkIndexFile(r io.ReaderAt, fn func(key types.NeedleId, offset types.Offse
 	return e
 }
 
+func WalkIndexFileIncrent(r io.ReaderAt, milestone uint64, fn func(key types.NeedleId, offset types.Offset, size types.Size) error) error {
+	var readerOffset = int64(milestone * types.NeedleMapEntrySize)
+	bytes := make([]byte, types.NeedleMapEntrySize*RowsToRead)
+	count, e := r.ReadAt(bytes, readerOffset)
+	if count == 0 && e == io.EOF {
+		return nil
+	}
+	glog.V(3).Infof("readerOffset %d count %d err: %v", readerOffset, count, e)
+	readerOffset += int64(count)
+	var (
+		key    types.NeedleId
+		offset types.Offset
+		size   types.Size
+		i      int
+	)
+
+	for count > 0 && e == nil || e == io.EOF {
+		for i = 0; i+types.NeedleMapEntrySize <= count; i += types.NeedleMapEntrySize {
+			key, offset, size = IdxFileEntry(bytes[i : i+types.NeedleMapEntrySize])
+			if e = fn(key, offset, size); e != nil {
+				return e
+			}
+		}
+		if e == io.EOF {
+			return nil
+		}
+		count, e = r.ReadAt(bytes, readerOffset)
+		glog.V(3).Infof("readerOffset %d count %d err: %v", readerOffset, count, e)
+		readerOffset += int64(count)
+	}
+	return e
+}
+
 func IdxFileEntry(bytes []byte) (key types.NeedleId, offset types.Offset, size types.Size) {
 	key = types.BytesToNeedleId(bytes[:types.NeedleIdSize])
 	offset = types.BytesToOffset(bytes[types.NeedleIdSize : types.NeedleIdSize+types.OffsetSize])
diff --git a/weed/storage/needle_map_leveldb.go b/weed/storage/needle_map_leveldb.go
index 31c86d124..f014797df 100644
--- a/weed/storage/needle_map_leveldb.go
+++ b/weed/storage/needle_map_leveldb.go
@@ -4,11 +4,14 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/syndtr/goleveldb/leveldb/errors"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 
 	"github.com/chrislusf/seaweedfs/weed/storage/idx"
+	"github.com/chrislusf/seaweedfs/weed/storage/types"
+	"github.com/chrislusf/seaweedfs/weed/util"
 
 	"github.com/syndtr/goleveldb/leveldb"
 
@@ -17,26 +20,36 @@ import (
 	. "github.com/chrislusf/seaweedfs/weed/storage/types"
 )
 
+//use "2 >> 16" to reduce cpu cost
+const milestoneCnt = 40
+const milestoneKey = 0xffffffffffffffff - 1
+
 type LevelDbNeedleMap struct {
 	baseNeedleMapper
 	dbFileName string
 	db         *leveldb.DB
+	recordNum  uint64
 }
 
 func NewLevelDbNeedleMap(dbFileName string, indexFile *os.File, opts *opt.Options) (m *LevelDbNeedleMap, err error) {
+	glog.V(0).Infof("NewLevelDbNeedleMap pocessing %s...", indexFile.Name())
+	db, errd := leveldb.OpenFile(dbFileName, opts)
+	glog.V(0).Infof("begain %v  %s %d", errd, dbFileName, getMileStone(db))
+	db.Close()
+
 	m = &LevelDbNeedleMap{dbFileName: dbFileName}
 	m.indexFile = indexFile
 	if !isLevelDbFresh(dbFileName, indexFile) {
-		glog.V(1).Infof("Start to Generate %s from %s", dbFileName, indexFile.Name())
+		glog.V(0).Infof("Start to Generate %s from %s", dbFileName, indexFile.Name())
 		generateLevelDbFile(dbFileName, indexFile)
-		glog.V(1).Infof("Finished Generating %s from %s", dbFileName, indexFile.Name())
+		glog.V(0).Infof("Finished Generating %s from %s", dbFileName, indexFile.Name())
 	}
 	if stat, err := indexFile.Stat(); err != nil {
 		glog.Fatalf("stat file %s: %v", indexFile.Name(), err)
 	} else {
 		m.indexFileOffset = stat.Size()
 	}
-	glog.V(1).Infof("Opening %s...", dbFileName)
+	glog.V(0).Infof("Opening %s...", dbFileName)
 
 	if m.db, err = leveldb.OpenFile(dbFileName, opts); err != nil {
 		if errors.IsCorrupted(err) {
@@ -46,11 +59,19 @@ func NewLevelDbNeedleMap(dbFileName string, indexFile *os.File, opts *opt.Option
 			return
 		}
 	}
-	glog.V(1).Infof("Loading %s...", indexFile.Name())
+	glog.V(0).Infof("getMileStone %s : %d", dbFileName, getMileStone(m.db))
+	m.recordNum = uint64(m.indexFileOffset / types.NeedleMapEntrySize)
+	milestone := (m.recordNum / milestoneCnt) * milestoneCnt
+	err = setMileStone(m.db, milestone)
+	if err != nil {
+		return
+	}
+	glog.V(0).Infof("Loading %s... %d %d", indexFile.Name(), milestone, getMileStone(m.db))
 	mm, indexLoadError := newNeedleMapMetricFromIndexFile(indexFile)
 	if indexLoadError != nil {
 		return nil, indexLoadError
 	}
+	glog.V(0).Infof("finish Loading %s...", indexFile.Name())
 	m.mapMetric = *mm
 	return
 }
@@ -78,9 +99,21 @@ func generateLevelDbFile(dbFileName string, indexFile *os.File) error {
 		return err
 	}
 	defer db.Close()
-	return idx.WalkIndexFile(indexFile, func(key NeedleId, offset Offset, size Size) error {
+
+	milestone := getMileStone(db)
+	if stat, err := indexFile.Stat(); err != nil {
+		glog.Fatalf("stat file %s: %v", indexFile.Name(), err)
+		return err
+	} else {
+		if milestone*types.NeedleMapEntrySize > uint64(stat.Size()) {
+			glog.Warningf("wrong milestone %d for filesize %d, set milestone to 0", milestone, stat.Size())
+			milestone = 0
+		}
+		glog.V(0).Infof("generateLevelDbFile %s, milestone %d, num of entries:%d", dbFileName, milestone, (uint64(stat.Size())-milestone*types.NeedleMapEntrySize)/types.NeedleMapEntrySize)
+	}
+	return idx.WalkIndexFileIncrent(indexFile, milestone, func(key NeedleId, offset Offset, size Size) error {
 		if !offset.IsZero() && size.IsValid() {
-			levelDbWrite(db, key, offset, size)
+			levelDbWrite(db, key, offset, size, 0)
 		} else {
 			levelDbDelete(db, key)
 		}
@@ -102,6 +135,7 @@ func (m *LevelDbNeedleMap) Get(key NeedleId) (element *needle_map.NeedleValue, o
 
 func (m *LevelDbNeedleMap) Put(key NeedleId, offset Offset, size Size) error {
 	var oldSize Size
+	var milestone uint64
 	if oldNeedle, ok := m.Get(key); ok {
 		oldSize = oldNeedle.Size
 	}
@@ -110,16 +144,61 @@ func (m *LevelDbNeedleMap) Put(key NeedleId, offset Offset, size Size) error {
 	if err := m.appendToIndexFile(key, offset, size); err != nil {
 		return fmt.Errorf("cannot write to indexfile %s: %v", m.indexFile.Name(), err)
 	}
-	return levelDbWrite(m.db, key, offset, size)
+	//atomic.AddUint64(&m.recordNum, 1)
+	//milestone = atomic.LoadUint64(&m.recordNum)
+	m.recordNum++
+	if m.recordNum%milestoneCnt != 0 {
+		milestone = 0
+	} else {
+		milestone = (m.recordNum / milestoneCnt) * milestoneCnt
+		glog.V(0).Infof("put cnt:%d milestone:%s %d", m.recordNum, m.dbFileName, milestone)
+	}
+	return levelDbWrite(m.db, key, offset, size, milestone)
 }
 
-func levelDbWrite(db *leveldb.DB, key NeedleId, offset Offset, size Size) error {
+func getMileStone(db *leveldb.DB) uint64 {
+	var mskBytes = make([]byte, 8)
+	util.Uint64toBytes(mskBytes, milestoneKey)
+	data, err := db.Get(mskBytes, nil)
+	if err != nil || len(data) != 8 {
+		glog.Warningf("get milestone from db error: %v, %d", err, len(data))
+		if !strings.Contains(strings.ToLower(err.Error()), "not found") {
+			err = setMileStone(db, 0)
+			if err != nil {
+				glog.Errorf("failed to set milestone: %v", err)
+			}
+		}
+
+		return 0
+	}
+	return util.BytesToUint64(data)
+}
+
+func setMileStone(db *leveldb.DB, milestone uint64) error {
+	glog.V(0).Infof("set milestone %d", milestone)
+	var mskBytes = make([]byte, 8)
+	util.Uint64toBytes(mskBytes, milestoneKey)
+	var msBytes = make([]byte, 8)
+	util.Uint64toBytes(msBytes, milestone)
+	if err := db.Put(mskBytes, msBytes, nil); err != nil {
+		return fmt.Errorf("failed to setMileStone: %v", err)
+	}
+	glog.V(0).Infof("ssset milestone %d, %d", milestone, getMileStone(db))
+	return nil
+}
+
+func levelDbWrite(db *leveldb.DB, key NeedleId, offset Offset, size Size, milestone uint64) error {
 
 	bytes := needle_map.ToBytes(key, offset, size)
 
 	if err := db.Put(bytes[0:NeedleIdSize], bytes[NeedleIdSize:NeedleIdSize+OffsetSize+SizeSize], nil); err != nil {
 		return fmt.Errorf("failed to write leveldb: %v", err)
 	}
+	// set milestone
+	if milestone != 0 {
+		glog.V(0).Infof("actually set milestone %d", milestone)
+		return setMileStone(db, milestone)
+	}
 	return nil
 }
 func levelDbDelete(db *leveldb.DB, key NeedleId) error {
@@ -129,6 +208,7 @@ func levelDbDelete(db *leveldb.DB, key NeedleId) error {
 }
 
 func (m *LevelDbNeedleMap) Delete(key NeedleId, offset Offset) error {
+	var milestone uint64
 	oldNeedle, found := m.Get(key)
 	if !found || oldNeedle.Size.IsDeleted() {
 		return nil
@@ -139,8 +219,16 @@ func (m *LevelDbNeedleMap) Delete(key NeedleId, offset Offset) error {
 	if err := m.appendToIndexFile(key, offset, TombstoneFileSize); err != nil {
 		return err
 	}
-
-	return levelDbWrite(m.db, key, oldNeedle.Offset, -oldNeedle.Size)
+	//atomic.AddUint64(&m.recordNum, 1)
+	//milestone = atomic.LoadUint64(&m.recordNum)
+	m.recordNum++
+	if m.recordNum%milestoneCnt != 0 {
+		milestone = 0
+	} else {
+		milestone = (m.recordNum / milestoneCnt) * milestoneCnt
+	}
+	glog.V(0).Infof("delete cnt:%d milestone:%s %d", m.recordNum, m.dbFileName, milestone)
+	return levelDbWrite(m.db, key, oldNeedle.Offset, -oldNeedle.Size, milestone)
 }
 
 func (m *LevelDbNeedleMap) Close() {