We performed an EBS R12.2 RAC to RAC clone and after successful completion of cloning we were not able to connect database using sqlplus command and it was giving the below error:

[oracle@racnode1 12.1.0]$ sqlplus apps@EBSRAC1
SQL*Plus: Release 12.1.0.2.0 Production on Tue Feb 14 08:25:38 2017
Copyright (c) 1982, 2014, Oracle. All rights reserved.
Enter password:
ERROR:
ORA-12537: TNS:connection closed

Solution:

There is an issue with the permission on oracle binary and its not allowing the connections.

[oracle@racnode1 12.1.0]$ ls -lrt bin/oracle
-rwxr-x--x. 1 oracle oinstall 324002305 Dec 19 13:34 bin/oracle

Change the permissions as mentioned below and it will work:

[oracle@racnode1 12.1.0]$ chmod 6751 bin/oracle
[oracle@racnode1 12.1.0]$ ls -lrt bin/oracle
-rwsr-s--x. 1 oracle oinstall 324002305 Dec 19 13:34 bin/oracle
[oracle@racnode1 12.1.0]$

Thanks for reading.

regards,

X A H E E R