How to rename RAC instance

currently we have DUP5(DUP51,DUP52) rac database

[oracle@ol6-112-rac1 ~]$ srvctl status database -d dup5
Instance DUP51 is running on node ol6-112-rac1
Instance DUP52 is running on node ol6-112-rac2

we want to rename instances to DUP5_1 and DUP5_2

create the pfile and make changes

[oracle@ol6-112-rac1 ~]$ export ORACLE_SID=DUP51
[oracle@ol6-112-rac1 ~]$ sqlplus
/as sys
SQL*Plus: Release 11.2.0.3.0 Production on Fri Jun 19 21:42:14 2020

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Enter user-name: dba

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options

DUP51@ol6-112-rac1 > create pfile='/tmp/11.ora' from spfile;

File created.

Current pfile

[oracle@ol6-112-rac1 dbs]$ cat /tmp/11.ora
DUP51.__db_cache_size=150994944
DUP52.__db_cache_size=138412032
DUP51.__java_pool_size=4194304
DUP52.__java_pool_size=4194304
DUP51.__large_pool_size=4194304
DUP52.__large_pool_size=4194304
DUP51.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environment
DUP51.__pga_aggregate_target=369098752
DUP52.__pga_aggregate_target=369098752
DUP51.__sga_target=314572800
DUP52.__sga_target=314572800
DUP51.__shared_io_pool_size=0
DUP52.__shared_io_pool_size=0
DUP51.__shared_pool_size=146800640
DUP52.__shared_pool_size=159383552
DUP51.__streams_pool_size=0
DUP52.__streams_pool_size=0
*.archive_lag_target=0
*.audit_file_dest='/u01/app/oracle/admin/DUP5/adump'
*.audit_trail='db'
*.cluster_database=TRUE
*.compatible='11.2.0.0.0'
*.control_files='+DATA/dup5/controlfile/current.612.1043517675'#Set by RMAN
*.db_block_size=8192
*.db_create_file_dest='+DATA'
*.db_domain='localdomain'
*.db_file_name_convert='+DATA','+DATA'
*.db_name='DUP5'#Reset to original value by RMAN
*.db_recovery_file_dest_size=1073741824
*.db_recovery_file_dest='+DATA'
*.dg_broker_start=TRUE
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=DUP5XDB)'
DUP51.instance_number=1
DUP52.instance_number=2
*.log_archive_dest_1='location=USE_DB_RECOVERY_FILE_DEST','valid_for=(ALL_LOGFILES, ALL_ROLES)'
*.log_archive_dest_state_2='ENABLE'
*.log_archive_format='DUP5_%t_%s_%r.arc'
*.log_archive_max_processes=30
*.log_archive_min_succeed_dest=1
*.log_file_name_convert='+DATA','+DATA'
*.open_cursors=300
*.pga_aggregate_target=367001600
*.processes=150
*.remote_listener='ol6-112-scan:1521'
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_max_size=629145600
*.sga_target=314572800
*.standby_file_management='AUTO'
DUP51.thread=1
DUP52.thread=2
DUP51.undo_tablespace='UNDOTBS1'
DUP52.undo_tablespace='UNDOTBS2'

pfile after changes

DUP5_1.__db_cache_size=150994944
DUP5_2.__db_cache_size=138412032
DUP5_1.__java_pool_size=4194304
DUP5_2.__java_pool_size=4194304
DUP5_1.__large_pool_size=4194304
DUP5_2.__large_pool_size=4194304
DUP5_1.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environment
DUP5_1.__pga_aggregate_target=369098752
DUP5_2.__pga_aggregate_target=369098752
DUP5_1.__sga_target=314572800
DUP5_2.__sga_target=314572800
DUP5_1.__shared_io_pool_size=0
DUP5_2.__shared_io_pool_size=0
DUP5_1.__shared_pool_size=146800640
DUP5_2.__shared_pool_size=159383552
DUP5_1.__streams_pool_size=0
DUP5_2.__streams_pool_size=0
*.archive_lag_target=0
*.audit_file_dest='/u01/app/oracle/admin/DUP5/adump'
*.audit_trail='db'
*.cluster_database=TRUE
*.compatible='11.2.0.0.0'
*.control_files='+DATA/dup5/controlfile/current.612.1043517675'#Set by RMAN
*.db_block_size=8192
*.db_create_file_dest='+DATA'
*.db_domain='localdomain'
*.db_file_name_convert='+DATA','+DATA'
*.db_name='DUP5'#Reset to original value by RMAN
*.db_recovery_file_dest_size=1073741824
*.db_recovery_file_dest='+DATA'
*.dg_broker_start=TRUE
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=DUP5XDB)'
DUP5_1.instance_number=1
DUP5_2.instance_number=2
*.log_archive_dest_1='location=USE_DB_RECOVERY_FILE_DEST','valid_for=(ALL_LOGFILES, ALL_ROLES)'
*.log_archive_dest_state_2='ENABLE'
*.log_archive_format='DUP5_%t_%s_%r.arc'
*.log_archive_max_processes=30
*.log_archive_min_succeed_dest=1
*.log_file_name_convert='+DATA','+DATA'
*.open_cursors=300
*.pga_aggregate_target=367001600
*.processes=150
*.remote_listener='ol6-112-scan:1521'
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_max_size=629145600
*.sga_target=314572800
*.standby_file_management='AUTO'
DUP5_1.thread=1
DUP5_2.thread=2
DUP5_1.undo_tablespace='UNDOTBS1'
DUP5_2.undo_tablespace='UNDOTBS2'

create a new password file on all the nodes with new instance SID names

[oracle@ol6-112-rac1 dbs]$ orapwd file=/u01/app/oracle/product/11.2.0.3/db_1/dbs/orapwdup5_1 password=oracle entries=10

[oracle@ol6-112-rac2 ~]$ orapwd file=/u01/app/oracle/product/11.2.0.3/db_1/dbs/orapwdup5_2 password=oracle entries=10

add oratab if you want to set env

ol6-112-rac1

DUP5_1:/u01/app/oracle/product/11.2.0.3/db_1:N            # line added by Agent

ol6-112-rac2

DUP5_2:/u01/app/oracle/product/11.2.0.3/db_1:N            # line added by Agent

set the environment

[oracle@ol6-112-rac1 dbs]$ . oraenv
ORACLE_SID = [DUP51] ? DUP5_1
The Oracle base remains unchanged with value /u01/app/oracle
[oracle@ol6-112-rac1 dbs]$ env|grep ORA
ORACLE_UNQNAME=TROY
ORACLE_SID=DUP5_1
ORACLE_BASE=/u01/app/oracle
ORACLE_HOSTNAME=ol6-112-rac1.localdomain
ORACLE_TERM=xterm
ORACLE_HOME=/u01/app/oracle/product/11.2.0.3/db_1

stop the database

[oracle@ol6-112-rac1 dbs]$ srvctl stop database -d dup5

create spfile from the modified pfile

i will first verify if we are able to nomount the db with the modified pfile

[oracle@ol6-112-rac1 dbs]$ sqlplus

SQL*Plus: Release 11.2.0.3.0 Production on Fri Jun 19 22:05:40 2020

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Enter user-name: /as sysdba
Connected to an idle instance.

DUP5_1@ol6-112-rac1 > startup nomount pfile='/tmp/1111.ora'
ORACLE instance started.

Total System Global Area  626327552 bytes
Fixed Size                  2230952 bytes
Variable Size             469763416 bytes
Database Buffers          150994944 bytes
Redo Buffers                3338240 bytes
DUP5_1@ol6-112-rac1 > create SPFILE='+DATA/dup5/spfiledup5.ora' from pfile='/tmp/11.ora';

File created.

so we are able to nomount the db. now lets shutdown the db

DUP5_1@ol6-112-rac1 > shu immediate
ORA-01507: database not mounted


ORACLE instance shut down.

rename the pfile as per new instance names and ensure that they have only spfile location entry only on both nodes

[oracle@ol6-112-rac1 dbs]$ cp initDUP51.ora initDUP5_1.ora
[oracle@ol6-112-rac1 dbs]$ cat initDUP5_1.ora
SPFILE='+DATA/DUP5/spfiledup5.ora'              # line added by Agent


[oracle@ol6-112-rac2 dbs]$ cp initDUP52.ora initDUP5_2.ora
[oracle@ol6-112-rac2 dbs]$ cat initDUP5_2.ora
SPFILE='+DATA/DUP5/spfiledup5.ora'              # line added by Agent
[oracle@ol6-112-rac2 dbs]$

remove old instance name from srvctl configuration and add new instance name

check status of db it should be down

[oracle@ol6-112-rac2 dbs]$ srvctl status database -d dup5
Instance DUP51 is not running on node ol6-112-rac1
Instance DUP52 is not running on node ol6-112-rac2

remove old instance

[oracle@ol6-112-rac2 dbs]$ srvctl remove instance -i DUP51 -d DUP5
Remove instance from the database DUP5? (y/[n]) y
[oracle@ol6-112-rac2 dbs]$ srvctl remove instance -i DUP52 -d DUP5
Remove instance from the database DUP5? (y/[n]) y

add new instances

[oracle@ol6-112-rac2 dbs]$ srvctl add instance -i DUP5_1 -d DUP5 -n ol6-112-rac1
[oracle@ol6-112-rac2 dbs]$ srvctl add instance -i DUP5_2 -d DUP5 -n ol6-112-rac2
[oracle@ol6-112-rac2 dbs]$ srvctl status database -d DUP5
Instance DUP5_1 is not running on node ol6-112-rac1
Instance DUP5_2 is not running on node ol6-112-rac2

start the db

[oracle@ol6-112-rac2 dbs]$ srvctl start database -d DUP5
[oracle@ol6-112-rac2 dbs]$ srvctl status database -d DUP5
Instance DUP5_1 is running on node ol6-112-rac1
Instance DUP5_2 is running on node ol6-112-rac2

check config

[oracle@ol6-112-rac2 dbs]$ srvctl config database -d DUP5
Database unique name: DUP5
Database name: DUP5
Oracle home: /u01/app/oracle/product/11.2.0.3/db_1
Oracle user: oracle
Spfile: +DATA/DUP5/spfiledup5.ora
Domain: localdomain
Start options: open
Stop options: immediate
Database role: PRIMARY
Management policy: AUTOMATIC
Server pools: DUP5
Database instances: DUP5_1,DUP5_2
Disk Groups: DATA
Mount point paths:
Services:
Type: RAC
Database is administrator managed