updated needle with fsync

weed/storage/volume_vacuum.go

@@ -289,6 +289,9 @@ func (v *Volume) makeupDiff(newDatFileName, newIdxFileName, oldDatFileName, oldI
 				return fmt.Errorf("ReadNeedleBlob %s key %d offset %d size %d failed: %v", oldDatFile.Name(), key, increIdxEntry.offset.ToActualOffset(), increIdxEntry.size, err)
 			}
 			dstDatBackend.Write(needleBytes)
+			if err := dstDatBackend.Sync(); err != nil {
+				return fmt.Errorf("cannot sync needle %s: %v", dstDatBackend.File.Name(), err)
+			}
 			util.Uint32toBytes(idxEntryBytes[8:12], uint32(offset/NeedlePaddingSize))
 		} else { //deleted needle
 			//fakeDelNeedle 's default Data field is nil
@@ -308,6 +311,12 @@ func (v *Volume) makeupDiff(newDatFileName, newIdxFileName, oldDatFileName, oldI
 				newIdxFileName, err)
 		}
 		_, err = idx.Write(idxEntryBytes)
+		if err != nil {
+			return fmt.Errorf("cannot write indexfile %s: %v", newIdxFileName, err)
+		}
+		if err := idx.Sync(); err != nil {
+			return fmt.Errorf("cannot sync indexfile %s: %v", newIdxFileName, err)
+		}
 	}
 
 	return nil