diff --git a/weed/command/export.go b/weed/command/export.go
index 0e2e7ccd9..3ea4b00d3 100644
--- a/weed/command/export.go
+++ b/weed/command/export.go
@@ -111,7 +111,7 @@ func (scanner *VolumeFileScanner4Export) VisitNeedle(n *needle.Needle, offset in
 	nv, ok := needleMap.Get(n.Id)
 	glog.V(3).Infof("key %d offset %d size %d disk_size %d compressed %v ok %v nv %+v",
 		n.Id, offset, n.Size, n.DiskSize(scanner.version), n.IsCompressed(), ok, nv)
-	if ok && nv.Size > 0 && nv.Size != types.TombstoneFileSize && nv.Offset.ToAcutalOffset() == offset {
+	if ok && nv.Size.IsValid() && nv.Offset.ToAcutalOffset() == offset {
 		if newerThanUnix >= 0 && n.HasLastModifiedDate() && n.LastModified < uint64(newerThanUnix) {
 			glog.V(3).Infof("Skipping this file, as it's old enough: LastModified %d vs %d",
 				n.LastModified, newerThanUnix)
diff --git a/weed/command/fix.go b/weed/command/fix.go
index e1455790f..ae9a051b8 100644
--- a/weed/command/fix.go
+++ b/weed/command/fix.go
@@ -48,7 +48,7 @@ func (scanner *VolumeFileScanner4Fix) ReadNeedleBody() bool {
 
 func (scanner *VolumeFileScanner4Fix) VisitNeedle(n *needle.Needle, offset int64, needleHeader, needleBody []byte) error {
 	glog.V(2).Infof("key %d offset %d size %d disk_size %d compressed %v", n.Id, offset, n.Size, n.DiskSize(scanner.version), n.IsCompressed())
-	if n.Size > 0 && n.Size != types.TombstoneFileSize {
+	if n.Size.IsValid() {
 		pe := scanner.nm.Set(n.Id, types.ToOffset(offset), n.Size)
 		glog.V(2).Infof("saved %d with error %v", n.Size, pe)
 	} else {
diff --git a/weed/storage/erasure_coding/ec_volume_delete.go b/weed/storage/erasure_coding/ec_volume_delete.go
index 822a9e923..a7f8c24a3 100644
--- a/weed/storage/erasure_coding/ec_volume_delete.go
+++ b/weed/storage/erasure_coding/ec_volume_delete.go
@@ -12,7 +12,7 @@ import (
 var (
 	MarkNeedleDeleted = func(file *os.File, offset int64) error {
 		b := make([]byte, types.SizeSize)
-		util.Uint32toBytes(b, types.TombstoneFileSize)
+		types.SizeToBytes(b, types.TombstoneFileSize)
 		n, err := file.WriteAt(b, offset+types.NeedleIdSize+types.OffsetSize)
 		if err != nil {
 			return fmt.Errorf("sorted needle write error: %v", err)
diff --git a/weed/storage/needle_map/compact_map.go b/weed/storage/needle_map/compact_map.go
index c1fb00268..81ff27c45 100644
--- a/weed/storage/needle_map/compact_map.go
+++ b/weed/storage/needle_map/compact_map.go
@@ -115,12 +115,9 @@ func (cs *CompactSection) deleteOverflowEntry(key SectionalNeedleId) {
 		return cs.overflow[i].Key >= key
 	})
 	if deleteCandidate != length && cs.overflow[deleteCandidate].Key == key {
-		for i := deleteCandidate; i < length-1; i++ {
-			cs.overflow[i] = cs.overflow[i+1]
-			cs.overflowExtra[i] = cs.overflowExtra[i+1]
+		if cs.overflow[deleteCandidate].Size.IsValid() {
+			cs.overflow[deleteCandidate].Size = - cs.overflow[deleteCandidate].Size
 		}
-		cs.overflow = cs.overflow[0 : length-1]
-		cs.overflowExtra = cs.overflowExtra[0 : length-1]
 	}
 }
 
@@ -132,7 +129,7 @@ func (cs *CompactSection) Delete(key NeedleId) Size {
 	if i := cs.binarySearchValues(skey); i >= 0 {
 		if cs.values[i].Size > 0 && cs.values[i].Size.IsValid() {
 			ret = cs.values[i].Size
-			cs.values[i].Size = TombstoneFileSize
+			cs.values[i].Size = -cs.values[i].Size
 		}
 	}
 	if _, v, found := cs.findOverflowEntry(skey); found {
diff --git a/weed/storage/needle_map_leveldb.go b/weed/storage/needle_map_leveldb.go
index 4a17e6d0e..415cd14dd 100644
--- a/weed/storage/needle_map_leveldb.go
+++ b/weed/storage/needle_map_leveldb.go
@@ -124,14 +124,18 @@ func levelDbDelete(db *leveldb.DB, key NeedleId) error {
 }
 
 func (m *LevelDbNeedleMap) Delete(key NeedleId, offset Offset) error {
-	if oldNeedle, ok := m.Get(key); ok {
-		m.logDelete(oldNeedle.Size)
+	oldNeedle, found := m.Get(key)
+	if !found || oldNeedle.Size.IsDeleted() {
+		return nil
 	}
+	m.logDelete(oldNeedle.Size)
+
 	// write to index file first
 	if err := m.appendToIndexFile(key, offset, TombstoneFileSize); err != nil {
 		return err
 	}
-	return levelDbDelete(m.db, key)
+
+	return levelDbWrite(m.db, key, oldNeedle.Offset, -oldNeedle.Size)
 }
 
 func (m *LevelDbNeedleMap) Close() {
diff --git a/weed/storage/types/needle_types.go b/weed/storage/types/needle_types.go
index 0e9115c0d..7e30d2bd8 100644
--- a/weed/storage/types/needle_types.go
+++ b/weed/storage/types/needle_types.go
@@ -2,7 +2,6 @@ package types
 
 import (
 	"fmt"
-	"math"
 	"strconv"
 
 	"github.com/chrislusf/seaweedfs/weed/util"
@@ -13,13 +12,13 @@ type Offset struct {
 	OffsetLower
 }
 
-type Size uint32
+type Size int32
 
 func (s Size) IsDeleted() bool {
-	return s == TombstoneFileSize
+	return s < 0 || s == TombstoneFileSize
 }
 func (s Size) IsValid() bool {
-	return s != TombstoneFileSize
+	return s >0 && s != TombstoneFileSize
 }
 
 type OffsetLower struct {
@@ -37,7 +36,7 @@ const (
 	NeedleMapEntrySize = NeedleIdSize + OffsetSize + SizeSize
 	TimestampSize      = 8 // int64 size
 	NeedlePaddingSize  = 8
-	TombstoneFileSize  = math.MaxUint32
+	TombstoneFileSize  = Size(-1)
 	CookieSize         = 4
 )
 
diff --git a/weed/storage/volume_read_write.go b/weed/storage/volume_read_write.go
index b2487dde0..4a997832c 100644
--- a/weed/storage/volume_read_write.go
+++ b/weed/storage/volume_read_write.go
@@ -195,7 +195,7 @@ func (v *Volume) syncDelete(n *needle.Needle) (Size, error) {
 	}
 
 	nv, ok := v.nm.Get(n.Id)
-	//fmt.Println("key", n.Id, "volume offset", nv.Offset, "data_size", n.Size, "cached size", nv.Size)
+	// fmt.Println("key", n.Id, "volume offset", nv.Offset, "data_size", n.Size, "cached size", nv.Size)
 	if ok && nv.Size.IsValid() {
 		size := nv.Size
 		n.Data = nil
@@ -233,7 +233,7 @@ func (v *Volume) deleteNeedle2(n *needle.Needle) (Size, error) {
 func (v *Volume) doDeleteRequest(n *needle.Needle) (Size, error) {
 	glog.V(4).Infof("delete needle %s", needle.NewFileIdFromNeedle(v.Id, n).String())
 	nv, ok := v.nm.Get(n.Id)
-	//fmt.Println("key", n.Id, "volume offset", nv.Offset, "data_size", n.Size, "cached size", nv.Size)
+	// fmt.Println("key", n.Id, "volume offset", nv.Offset, "data_size", n.Size, "cached size", nv.Size)
 	if ok && nv.Size.IsValid() {
 		size := nv.Size
 		n.Data = nil
@@ -260,13 +260,18 @@ func (v *Volume) readNeedle(n *needle.Needle, readOption *ReadOption) (int, erro
 	if !ok || nv.Offset.IsZero() {
 		return -1, ErrorNotFound
 	}
-	if nv.Size.IsDeleted() {
-		return -1, errors.New("already deleted")
+	readSize := nv.Size
+	if readSize.IsDeleted() {
+		if readOption != nil && readOption.ReadDeleted && readSize != TombstoneFileSize {
+			readSize = -readSize
+		} else {
+			return -1, errors.New("already deleted")
+		}
 	}
-	if nv.Size == 0 {
+	if readSize == 0 {
 		return 0, nil
 	}
-	err := n.ReadData(v.DataBackend, nv.Offset.ToAcutalOffset(), nv.Size, v.Version())
+	err := n.ReadData(v.DataBackend, nv.Offset.ToAcutalOffset(), readSize, v.Version())
 	if err != nil {
 		return 0, err
 	}
@@ -299,7 +304,7 @@ func (v *Volume) startWorker() {
 			currentBytesToWrite := int64(0)
 			for {
 				request, ok := <-v.asyncRequestsChan
-				//volume may be closed
+				// volume may be closed
 				if !ok {
 					chanClosed = true
 					break
@@ -402,8 +407,8 @@ func ScanVolumeFileFrom(version needle.Version, datBackend backend.BackendStorag
 		if volumeFileScanner.ReadNeedleBody() {
 			if needleBody, err = n.ReadNeedleBody(datBackend, version, offset+NeedleHeaderSize, rest); err != nil {
 				glog.V(0).Infof("cannot read needle body: %v", err)
-				//err = fmt.Errorf("cannot read needle body: %v", err)
-				//return
+				// err = fmt.Errorf("cannot read needle body: %v", err)
+				// return
 			}
 		}
 		err := volumeFileScanner.VisitNeedle(n, offset, nh, needleBody)