diff --git a/unmaintained/remove_duplicate_fids/remove_duplicate_fids.go b/unmaintained/remove_duplicate_fids/remove_duplicate_fids.go
new file mode 100644
index 000000000..5716ffa90
--- /dev/null
+++ b/unmaintained/remove_duplicate_fids/remove_duplicate_fids.go
@@ -0,0 +1,92 @@
+package main
+
+import (
+    "flag"
+
+    "github.com/chrislusf/seaweedfs/weed/glog"
+    "github.com/chrislusf/seaweedfs/weed/storage"
+    "github.com/chrislusf/seaweedfs/weed/storage/needle"
+    "os"
+    "path/filepath"
+
+    "fmt"
+)
+
+var (
+    volumePath       = flag.String("dir", "/tmp", "data directory to store files")
+    volumeCollection = flag.String("collection", "", "the volume collection name")
+    volumeId         = flag.Int("volumeId", -1, "a volume id. The volume should already exist in the dir. The volume index file should not exist.")
+)
+
+func Checksum(n* needle.Needle) string {
+     return fmt.Sprintf("%s%x", n.Id, n.Cookie)
+}
+
+type VolumeFileScanner4SeeDat struct {
+    version needle.Version
+    block storage.SuperBlock
+
+    dir    string
+    hashes map[string]bool
+    dat * os.File
+}
+
+func (scanner *VolumeFileScanner4SeeDat) VisitSuperBlock(superBlock storage.SuperBlock) error {
+    scanner.version = superBlock.Version()
+    scanner.block = superBlock
+    return nil
+
+}
+func (scanner *VolumeFileScanner4SeeDat) ReadNeedleBody() bool {
+    return true
+}
+
+func (scanner *VolumeFileScanner4SeeDat) VisitNeedle(n *needle.Needle, offset int64) error {
+
+    if scanner.dat == nil {
+	newDatFile, err := os.Create(filepath.Join(*volumePath, "dat_fixed"))
+	if err != nil {
+		glog.Fatalf("Write New Volume Data %v", err)
+	}
+	scanner.dat = newDatFile
+	scanner.dat.Write(scanner.block.Bytes())
+    }
+
+    checksum := Checksum(n)
+
+    if scanner.hashes[checksum] {
+        glog.V(0).Infof("duplicate checksum:%s fid:%d,%s%x @ offset:%d", checksum, *volumeId, n.Id, n.Cookie, offset)
+        return nil
+    }
+    scanner.hashes[checksum] = true
+
+    _, s, _, e := n.Append(scanner.dat, scanner.version)
+    fmt.Printf("size %d error %v\n", s, e)
+
+    return nil
+}
+
+func main() {
+    flag.Parse()
+
+    vid := needle.VolumeId(*volumeId)
+
+    outpath, _ := filepath.Abs(filepath.Dir(os.Args[0]))
+
+    scanner := &VolumeFileScanner4SeeDat{
+        dir:    filepath.Join(outpath, "out"),
+        hashes: map[string]bool{},
+    }
+
+    if _, err := os.Stat(scanner.dir); err != nil {
+        if err := os.MkdirAll(scanner.dir, os.ModePerm); err != nil {
+            glog.Fatalf("could not create output dir : %s", err)
+        }
+    }
+
+    err := storage.ScanVolumeFile(*volumePath, *volumeCollection, vid, storage.NeedleMapInMemory, scanner)
+    if err != nil {
+        glog.Fatalf("Reading Volume File [ERROR] %s\n", err)
+    }
+
+}