ORA-01034 ORA-27101 Linux-x86_64 Error: 2: No such file or directory

Error Found

ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory

Solution:

To resolve this make sure the Oracle Home locations is correct in the listener.ora file.

You can check the OH from where listener is running by running

ps -ef | grep tns

And correct the entries in the listener.ora file with the correct OH location.