anchor.diff:                                                %% replication update
                                                 %% will still work
                                                 %% properly.
  -                                              if Node /= NewNode ->
  +                                              if
  +                                                  Node =:= undefined ->
  +                                                      %% this handles
  +                                                      %% case of
  +                                                      %% missing
  +                                                      %% vbucket (like
  +                                                      %% after failing
  +                                                      %% over more
  +                                                      %% nodes then
  +                                                      %% replica
  +                                                      %% count)
  +                                                      ok;
  +                                                  Node /= NewNode ->
                                                         run_mover(Bucket, V, Node,
                                                                   NewNode, 2);
                                                    true ->
  
positive.code:                                     update_replication_pre_move(
                                        Bucket, V, OldChain, NewChain),
                                      spawn_link(
                                        Node,
                                        fun () ->
                                                process_flag(trap_exit, true),
                                                %% We do a no-op here
  
negative.code:     NewPairs = pairs(NewChain),
      %% Stop replication for any old pair that isn't needed any more.
      lists:foreach(
        fun ({SrcNode, DstNode}) when SrcNode =/= undefined ->
                ns_vbm_sup:kill_replica(Bucket, SrcNode, DstNode, VBucket)
        end, OldPairs -- NewPairs),
      %% Start replication for any new pair that wouldn't have already
  