PROBLEM:

While trying to rename a RAC database using nid utility, got below error.

NID-00120: Database should be mounted exclusively

nid target=sys/oracle dbname=PRODPREDM

DBNEWID: Release 12.1.0.2.0 - Production on Sun Jul 1 22:56:53 2018

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

Connected to database PRODMPD (DBID=678234706)

NID-00120: Database should be mounted exclusively


Change of database name failed during validation - database is intact.
DBNEWID - Completed with validation errors.

SOLUTION:

This error comes, when we keep the cluster_database parameter to TRUE.

As a prerequisite for renaming RAC database, make sure cluster_database parameter is set to FALSE.

alter system set cluster_database=FALSE scope=spfile ;

shutdown immediate;
startup nomount;

Now run the nid tool again. It will succeed.