diff --git a/go/storage/volume.go b/go/storage/volume.go
index bfdac8edf..937798649 100644
--- a/go/storage/volume.go
+++ b/go/storage/volume.go
@@ -346,44 +346,6 @@ func ScanVolumeFile(dirname string, collection string, id VolumeId,
 	return
 }
 
-func (v *Volume) copyDataAndGenerateIndexFile(dstName, idxName string) (err error) {
-	var (
-		dst, idx *os.File
-	)
-	if dst, err = os.OpenFile(dstName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644); err != nil {
-		return
-	}
-	defer dst.Close()
-
-	if idx, err = os.OpenFile(idxName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644); err != nil {
-		return
-	}
-	defer idx.Close()
-
-	nm := NewNeedleMap(idx)
-	new_offset := int64(SuperBlockSize)
-
-	err = ScanVolumeFile(v.dir, v.Collection, v.Id, func(superBlock SuperBlock) error {
-		_, err = dst.Write(superBlock.Bytes())
-		return err
-	}, func(n *Needle, offset int64) error {
-		nv, ok := v.nm.Get(n.Id)
-		glog.V(3).Infoln("needle expected offset ", offset, "ok", ok, "nv", nv)
-		if ok && int64(nv.Offset)*NeedlePaddingSize == offset && nv.Size > 0 {
-			if _, err = nm.Put(n.Id, uint32(new_offset/NeedlePaddingSize), n.Size); err != nil {
-				return fmt.Errorf("cannot put needle: %s", err)
-			}
-			if _, err = n.Append(dst, v.Version()); err != nil {
-				return fmt.Errorf("cannot append needle: %s", err)
-			}
-			new_offset += n.DiskSize()
-			glog.V(3).Infoln("saving key", n.Id, "volume offset", offset, "=>", new_offset, "data_size", n.Size)
-		}
-		return nil
-	})
-
-	return
-}
 func (v *Volume) ContentSize() uint64 {
 	return v.nm.ContentSize()
 }
diff --git a/go/storage/volume_vacuum.go b/go/storage/volume_vacuum.go
index 8b36bb378..3aeb11e64 100644
--- a/go/storage/volume_vacuum.go
+++ b/go/storage/volume_vacuum.go
@@ -2,6 +2,7 @@ package storage
 
 import (
 	"code.google.com/p/weed-fs/go/glog"
+	"fmt"
 	"os"
 )
 
@@ -33,3 +34,42 @@ func (v *Volume) commitCompact() error {
 	}
 	return nil
 }
+
+func (v *Volume) copyDataAndGenerateIndexFile(dstName, idxName string) (err error) {
+	var (
+		dst, idx *os.File
+	)
+	if dst, err = os.OpenFile(dstName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644); err != nil {
+		return
+	}
+	defer dst.Close()
+
+	if idx, err = os.OpenFile(idxName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644); err != nil {
+		return
+	}
+	defer idx.Close()
+
+	nm := NewNeedleMap(idx)
+	new_offset := int64(SuperBlockSize)
+
+	err = ScanVolumeFile(v.dir, v.Collection, v.Id, func(superBlock SuperBlock) error {
+		_, err = dst.Write(superBlock.Bytes())
+		return err
+	}, func(n *Needle, offset int64) error {
+		nv, ok := v.nm.Get(n.Id)
+		glog.V(3).Infoln("needle expected offset ", offset, "ok", ok, "nv", nv)
+		if ok && int64(nv.Offset)*NeedlePaddingSize == offset && nv.Size > 0 {
+			if _, err = nm.Put(n.Id, uint32(new_offset/NeedlePaddingSize), n.Size); err != nil {
+				return fmt.Errorf("cannot put needle: %s", err)
+			}
+			if _, err = n.Append(dst, v.Version()); err != nil {
+				return fmt.Errorf("cannot append needle: %s", err)
+			}
+			new_offset += n.DiskSize()
+			glog.V(3).Infoln("saving key", n.Id, "volume offset", offset, "=>", new_offset, "data_size", n.Size)
+		}
+		return nil
+	})
+
+	return
+}