duplicate command gets hung while restoring spfile

duplicate command gets hung while restoring spfile (not progressing at all)... two days it was running fine for other db... Can some give there thought

Recovery Manager: Release 12.1.0.2.0 - Production on Thu Apr 20 07:26:38 2017

Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.

connected to auxiliary database: IGL93D (not mounted)

RMAN> run

2> {

3> allocate auxiliary channel ch1 type disk;

4> allocate auxiliary channel ch2 type disk;

5> allocate auxiliary channel ch3 type disk;

6> allocate auxiliary channel ch4 type disk;

7> allocate auxiliary channel ch5 type disk;

8> allocate auxiliary channel ch6 type disk;

9> set until time "to_date('2017-04-20:06:18:00','yyyy-mm-dd:hh24:mi:ss')";