RMAN-06900: WARNING: unable to generate V$RMAN_STATUS

[oracle@test1]$ rman target /

Recovery Manager: Release 11.2.0.1.0 - Production on Tue Sep 29 14:49:43 2015

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

connected to target database: UCDB (DBID=995784007)

RMAN-06900: WARNING: unable to generate V$RMAN_STATUS or V$RMAN_OUTPUT row

RMAN-06901: WARNING: disabling update of the V$RMAN_STATUS and V$RMAN_OUTPUT rows

ORACLE error from target database: 

ORA-19921: maximum number of 128 rows exceeded

RMAN> 

RMAN> exit

后经多方查证，是其他机器也开了一个rman(不是指同一台机器) 关掉后就正常了使用