diff --git a/unmaintained/fix_dat/fix_dat.go b/unmaintained/fix_dat/fix_dat.go
index 84a2264ed..ae45f7cc8 100644
--- a/unmaintained/fix_dat/fix_dat.go
+++ b/unmaintained/fix_dat/fix_dat.go
@@ -107,7 +107,7 @@ func iterateEntries(datFile, idxFile *os.File, visitNeedle func(n *storage.Needl
 					fmt.Println("Recovered in f", r)
 				}
 			}()
-			if err = n.ReadNeedleBody(datFile, version, offset+int64(storage.NeedleHeaderSize), rest, false); err != nil {
+			if _, err = n.ReadNeedleBody(datFile, version, offset+int64(storage.NeedleHeaderSize), rest, false); err != nil {
 				fmt.Printf("cannot read needle body: offset %d body %d %v\n", offset, rest, err)
 			}
 		}()
diff --git a/weed/storage/needle_map.go b/weed/storage/needle_map.go
index 05bc6e86c..142018946 100644
--- a/weed/storage/needle_map.go
+++ b/weed/storage/needle_map.go
@@ -17,6 +17,10 @@ const (
 	NeedleMapBoltDb
 )
 
+const (
+	NeedleIndexSize = 16
+)
+
 type NeedleMapper interface {
 	Put(key uint64, offset uint32, size uint32) error
 	Get(key uint64) (element *NeedleValue, ok bool)
diff --git a/weed/storage/needle_read_write.go b/weed/storage/needle_read_write.go
index 9499c825d..c7115f800 100644
--- a/weed/storage/needle_read_write.go
+++ b/weed/storage/needle_read_write.go
@@ -226,37 +226,25 @@ func ReadNeedleHeader(r *os.File, version Version, offset int64) (n *Needle, bod
 
 //n should be a needle already read the header
 //the input stream will read until next file entry
-func (n *Needle) ReadNeedleBody(r *os.File, version Version, offset int64, bodyLength uint32, verifyCheckSum bool) (err error) {
+func (n *Needle) ReadNeedleBody(r *os.File, version Version, offset int64, bodyLength uint32) (bytes []byte, err error) {
 	if bodyLength <= 0 {
-		return nil
+		return
 	}
 	switch version {
 	case Version1:
-		bytes := make([]byte, bodyLength)
+		bytes = make([]byte, bodyLength)
 		if _, err = r.ReadAt(bytes, offset); err != nil {
 			return
 		}
 		n.Data = bytes[:n.Size]
 		n.Checksum = NewCRC(n.Data)
-		if verifyCheckSum {
-			checksum := util.BytesToUint32(bytes[n.Size : n.Size+NeedleChecksumSize])
-			if n.Checksum.Value() != checksum {
-				err = fmt.Errorf("CRC check failed")
-			}
-		}
 	case Version2:
-		bytes := make([]byte, bodyLength)
+		bytes = make([]byte, bodyLength)
 		if _, err = r.ReadAt(bytes, offset); err != nil {
 			return
 		}
 		n.readNeedleDataVersion2(bytes[0:n.Size])
 		n.Checksum = NewCRC(n.Data)
-		if verifyCheckSum {
-			checksum := util.BytesToUint32(bytes[n.Size : n.Size+NeedleChecksumSize])
-			if n.Checksum.Value() != checksum {
-				err = fmt.Errorf("CRC check failed")
-			}
-		}
 	default:
 		err = fmt.Errorf("Unsupported Version! (%d)", version)
 	}
diff --git a/weed/storage/volume.go b/weed/storage/volume.go
index b0ab9e008..43b239fd2 100644
--- a/weed/storage/volume.go
+++ b/weed/storage/volume.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )
 
 type Volume struct {
@@ -47,55 +48,64 @@ func loadVolumeWithoutIndex(dirname string, collection string, id VolumeId, need
 	return
 }
 func verifyIndexFileIntegrity(indexFile *os.File) (indexSize int64, err error) {
-	var fi os.FileInfo
-	if fi, err = indexFile.Stat(); err != nil {
-		return
-	} else if indexSize = fi.Size(); indexSize != 0 && indexSize%16 != 0 {
-		err = fmt.Errorf("index file %s's size is %d bytes, maybe corrupted", indexFile.Name(), fi.Size())
-		return
+	if indexSize, err = util.GetFileSize(indexFile); err == nil {
+		if indexSize%NeedleIndexSize != 0 {
+			err = fmt.Errorf("index file's size is %d bytes, maybe corrupted", indexSize)
+		}
 	}
 	return
 }
 func readIndexEntryAtOffset(indexFile *os.File, offset int64, v Version) (bytes []byte, err error) {
 	if offset < 0 {
-		err = fmt.Errorf("offset %d for index file %s is invalid", offset, indexFile.Name())
+		err = fmt.Errorf("offset %d for index file is invalid", offset)
 		return
 	}
-	bytes = make([]byte, 16)
+	bytes = make([]byte, NeedleIndexSize)
 	_, err = indexFile.ReadAt(bytes, offset)
 	return
 }
 func verifyNeedleIntegrity(datFile *os.File, v Version, offset int64, key uint64) error {
 	if n, bodyLength, err := ReadNeedleHeader(datFile, v, offset); err != nil {
-		return fmt.Errorf("can not read needle header: %s", err.Error())
+		return fmt.Errorf("can not read needle header: %v", err)
 	} else {
 		if n.Id != key {
 			return fmt.Errorf("index key %#x does not match needle's Id %#x", key, n.Id)
 		} else {
-			if err := n.ReadNeedleBody(datFile, v, offset+int64(NeedleHeaderSize), bodyLength, true); err != nil {
-				return fmt.Errorf("dat file %s's body reading failed: %s", datFile.Name(), err.Error())
+			if bytes, err := n.ReadNeedleBody(datFile, v, offset+int64(NeedleHeaderSize), bodyLength); err != nil {
+				return fmt.Errorf("dat file's body reading failed: %v", err)
+			} else {
+				checksum := util.BytesToUint32(bytes[n.Size : n.Size+NeedleChecksumSize])
+				if n.Checksum.Value() != checksum {
+					return fmt.Errorf("CRC check failed")
+				}
 			}
 		}
 	}
 	return nil
 }
-func volumeDataIntegrityChecking(v *Volume, indexFile *os.File) {
+func volumeDataIntegrityChecking(v *Volume, indexFile *os.File) error {
 	var indexSize int64
 	var e error
 	if indexSize, e = verifyIndexFileIntegrity(indexFile); e != nil {
-		glog.V(0).Infof("verifyIndexFileIntegrity failed %s", e.Error())
-		v.readOnly = true
+		return fmt.Errorf("verifyIndexFileIntegrity failed: %v", e)
 	}
-	var lastIdxEntry []byte
-	if lastIdxEntry, e = readIndexEntryAtOffset(indexFile, indexSize-16, v.Version()); e != nil {
-		glog.V(0).Infof("readLastIndexEntry failed %s", e.Error())
-		v.readOnly = true
-	}
-	key, offset, _ := idxFileEntry(lastIdxEntry)
-	if e = verifyNeedleIntegrity(v.dataFile, v.Version(), int64(offset)*NeedlePaddingSize, key); e != nil {
-		glog.V(0).Infof("verifyNeedleIntegrity failed %s", e.Error())
-		v.readOnly = true
+	if indexSize != 0 {
+		var lastIdxEntry []byte
+		if lastIdxEntry, e = readIndexEntryAtOffset(indexFile, indexSize-NeedleIndexSize, v.Version()); e != nil {
+			return fmt.Errorf("readLastIndexEntry failed: %v", e)
+		}
+		key, offset, _ := idxFileEntry(lastIdxEntry)
+		if e = verifyNeedleIntegrity(v.dataFile, v.Version(), int64(offset)*NeedlePaddingSize, key); e != nil {
+			return fmt.Errorf("verifyNeedleIntegrity failed: %v", e)
+		}
+	} else {
+		if datSize, err := util.GetFileSize(v.dataFile); err == nil {
+			if datSize > 0 {
+				return fmt.Errorf("dat file size is %d, not empty while the index file is empty!", datSize)
+			}
+		}
 	}
+	return nil
 }
 func (v *Volume) FileName() (fileName string) {
 	if v.Collection == "" {
@@ -156,7 +166,10 @@ func (v *Volume) load(alsoLoadIndex bool, createDatIfMissing bool, needleMapKind
 				return fmt.Errorf("cannot write Volume Index %s.idx: %v", fileName, e)
 			}
 		}
-		volumeDataIntegrityChecking(v, indexFile)
+		if e = volumeDataIntegrityChecking(v, indexFile); e != nil {
+			v.readOnly = true
+			glog.V(0).Infof("volumeDataIntegrityChecking failed %v", e)
+		}
 		switch needleMapKind {
 		case NeedleMapInMemory:
 			glog.V(0).Infoln("loading index file", fileName+".idx", "readonly", v.readOnly)
@@ -384,7 +397,7 @@ func ScanVolumeFile(dirname string, collection string, id VolumeId,
 	}
 	for n != nil {
 		if readNeedleBody {
-			if err = n.ReadNeedleBody(v.dataFile, version, offset+int64(NeedleHeaderSize), rest, false); err != nil {
+			if _, err = n.ReadNeedleBody(v.dataFile, version, offset+int64(NeedleHeaderSize), rest); err != nil {
 				glog.V(0).Infof("cannot read needle body: %v", err)
 				//err = fmt.Errorf("cannot read needle body: %v", err)
 				//return
diff --git a/weed/util/file_util.go b/weed/util/file_util.go
index a39fb0860..4461bdc51 100644
--- a/weed/util/file_util.go
+++ b/weed/util/file_util.go
@@ -36,3 +36,11 @@ func Readln(r *bufio.Reader) ([]byte, error) {
 	}
 	return ln, err
 }
+
+func GetFileSize(file *os.File) (size int64, err error) {
+	var fi os.FileInfo
+	if fi, err = file.Stat(); err == nil {
+		size = fi.Size()
+	}
+	return
+}