Create a RAC one node database from existing two node RAC in Oracle

Check the status for current running RAC instances:

[oracle@host01 ~]$ . oraenv
ORACLE_SID = [oracle] ? orcl
The Oracle base has been set to /u01/app/oracle
[oracle@host01 ~]$ 
[oracle@host01 ~]$ srvctl status database -db orcl
Instance orcl1 is running on node host01
Instance orcl2 is running on node host02

Remove the 2nd instance for RAC database configuration

[oracle@host01 ~]$ srvctl remove instance -db orcl -instance orcl2 -force

Verify the Oracle RAC database status

[oracle@host01 ~]$ srvctl status database -db orcl
Instance orcl1 is running on node host01

Add one service for Oracle RAC

[oracle@host01 ~]$ srvctl add service -db orcl -service SERV1 -preferred orcl1

Convert the RAC setting to one node RAC

[oracle@host01 ~]$ srvctl convert database -db orcl -dbtype RACONENODE -instance orcl

Check the status for RAC database

[oracle@host01 ~]$ srvctl config database -db orcl
Database unique name: orcl
Database name: orcl
Oracle home: /u01/app/oracle/product/19.3.0/dbhome_1
Oracle user: oracle
Spfile: +DATA/ORCL/PARAMETERFILE/spfile.272.1157786363
Password file: +DATA/ORCL/PASSWORD/pwdorcl.257.1157785563
Domain: 
Start options: open
Stop options: immediate
Database role: PRIMARY
Management policy: AUTOMATIC
Server pools: 
Disk Groups: FRA,DATA
Mount point paths: 
Services: actest,SERV1,srvhr,srvtest
Type: RACOneNode
Online relocation timeout: 30
Instance name prefix: orcl
Candidate servers: host01
OSDBA group: dba
OSOPER group: oper
Database instances: orcl_1
CSS critical: no
CPU count: 0
Memory target: 0
Maximum memory: 0
Default network number for database services: 
Database is administrator managed

Check the status of running database:

[oracle@host01 ~]$ srvctl status database -db orcl
Instance orcl1 is running on node host01
Online relocation: INACTIVE

Relocate the Service from one instance to another in One Node RAC

[HOST01 ADMIN] $ ssh oracle@host01

Last login: Fri Jan 12 12:03:32 2024 from host01.example.com

[oracle@host01 ~]$ 

[oracle@host01 ~]$ 

[oracle@host01 ~]$ . oraenv

ORACLE_SID = [oracle] ? orcl

The Oracle base has been set to /u01/app/oracle

[oracle@host01 ~]$ 

[oracle@host01 ~]$ 

[oracle@host01 ~]$ srvctl relocate database -db orcl -node host02 -timeout 15 -verbose

Added target node host02

Configuration updated to two instances

Instance orcl_2 started

Services relocated

Waiting for up to 15 minutes for instance orcl1 to stop ...

Instance orcl1 stopped

Configuration updated to one instance

Check the Status for Oracle Service after reallocate

[oracle@host01 ~]$ srvctl status database -db orcl

Instance orcl_2 is running on node host02

Online relocation: INACTIVE

[oracle@host01 ~]$