Error ORA-12547: TNS:lost contact Trying To Connect on SQLPLUS After Duplicate

At the end of a duplicate process and cluster environment configuration, I encountered an error commonly seen in network, communication, and net services configuration issues related to Oracle:

[oracle@xptosrv01 dbs]$ srvctl start instance -d xpto -i xpto01
[oracle@xptosrv01 dbs]$ sqlplus

SQL*Plus: Release 19.0.0.0.0 - Production on Thu Jul 18 13:24:29 2024
Version 19.23.0.0.0

Copyright (c) 1982, 2023, Oracle.  All rights reserved.

Enter user-name: /as sysdba
ERROR:
ORA-12547: TNS:lost contact


Enter user-name: ^C
[oracle@xptosrv01 dbs]$ srvctl config database -d xpto
Database unique name: xpto
Database name:
Oracle home: /u01/oracle/product/19.0.0.0/
Oracle user: oracle
Spfile: /u01/oracle/product/19.0.0.0/dbs/spfilexpto01.ora
Password file: +DGDATA/orapwxpto
Domain:
Start options: open
Stop options: immediate
Database role: PRIMARY
Management policy: AUTOMATIC
Server pools:
Disk Groups: DGDATA,DGARCH
Mount point paths:
Services:
Type: RAC
Start concurrency:
Stop concurrency:
OSDBA group: dba
OSOPER group: oper
Database instances: xpto01,xpto02
Configured nodes: xptoserv01,xptoserv02
CSS critical: no
CPU count: 0
Memory target: 0
Maximum memory: 0
Default network number for database services:
Database is administrator managed

The reason for this issue is almost unbelievable; however, it is simply a slash at the end of the ORACLE_HOME directory, as per Oracle’s Doc ID: Sqlplus Reports “ORA-12547: TNS:lost contact” But SRVCTL Shows Database Running (Doc ID 2975749.1).

[oracle@xptosrv01 dbs]$ srvctl modify database -d xpto -o /u01/oracle/product/19.0.0.0
[oracle@xptosrv01 dbs]$ srvctl config database -d xpto
Database unique name: xpto
Database name:
Oracle home: /u01/oracle/product/19.0.0.0
Oracle user: oracle
Spfile: /u01/oracle/product/19.0.0.0/dbs/spfilexpto01.ora
Password file: +DGDATA/orapwxpto
Domain:
Start options: open
Stop options: immediate
Database role: PRIMARY
Management policy: AUTOMATIC
Server pools:
Disk Groups: DGDATA,DGARCH
Mount point paths:
Services:
Type: RAC
Start concurrency:
Stop concurrency:
OSDBA group: dba
OSOPER group: oper
Database instances: xpto01,xpto02
Configured nodes: xptoserv01,xptoserv02
CSS critical: no
CPU count: 0
Memory target: 0
Maximum memory: 0
Default network number for database services:
Database is administrator managed

Restart the instance or the database and try to connect again:

[oracle@xptosrv01 dbs]$ srvctl stop instance -d xpto -i xpto01
[oracle@xptosrv01 dbs]$ srvctl start instance -d xpto -i xpto01
[oracle@xptosrv01 dbs]$ sqlplus

SQL*Plus: Release 19.0.0.0.0 - Production on Thu Jul 18 13:37:27 2024
Version 19.23.0.0.0

Copyright (c) 1982, 2023, Oracle.  All rights reserved.

Enter user-name: /as sysdba

Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.23.0.0.0

SQL>

Reference: Sqlplus Reports “ORA-12547: TNS:lost contact” But SRVCTL Shows Database Running