diff --git a/weed/storage/volume_vacuum.go b/weed/storage/volume_vacuum.go
index c8be1d9f5..5d712c7ff 100644
--- a/weed/storage/volume_vacuum.go
+++ b/weed/storage/volume_vacuum.go
@@ -381,6 +381,7 @@ func copyDataBasedOnIndexFile(srcDatName, srcIdxName, dstDatName, datIdxName str
 		return err
 	}
 	srcDatBackend = backend.NewDiskFile(dataFile)
+	defer srcDatBackend.Close()
 
 	now := uint64(time.Now().Unix())