Unable to connect using Net service name

[caljedi]

I'm running 10.2.0.3 on a RHEL 4 box. I am able to connect to Oracle locally using :

sqlplus username

however, if i try to login using:

sqlplus username@SID, i get this error message:

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

My sqlnet.ora file looks like this:
=======================
SQLNET.AUTHENTICATION_SERVICES=(NONE)
NAMES.DEFAULT_DOMAIN = world
NAMES.DIRECTORY_PATH=(TNSNAMES)
=============================

and my tnsnames.ora file looks like this:
===========================
testsid.world =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 1.2.3.4)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = testsid)
)
)
==================================
I've tried this with both SYSDBA users as well as standard users; also ran TNSPING on the box which returns a success code, so I'm not really sure what I'm missing here. Any help would be greatly appreciated.

 

[SantaMufasa]

Jedi,

These errors:

ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist

...indicate that the instance, to which Oracle thinks you are trying to connect, is not actually running.

Since you said...

I've tried this with both SYSDBA users...

...you apparently have necessary privileges to do the following mini-tests:

1) Connect to the operating system as a user that is a member of the Oracle DBA group.

2) Confirm both the default Oracle instance and the $ORACLE_HOME directory:

% echo $ORACLE_SID
% echo $ORACLE_HOME

3) If the above settings match your expectations, then from an o/s command prompt issue the following command:

% sqlplus /nolog

If that Oracle instance is running, then the above command responds with:

Connected.

If that Oracle instance is not running, then the above command responds with:

Connected to an idle instance.

4) If the instance is running, then a helpful follow-on query is:

SELECT * FROM V$INSTANCE;

The results of that query confirm information that you can correlate with the tnsnames.ora information.

Let us know your findings to this point, then we can proceed with additional troubleshooting.

Mufasa
(aka Dave of Sandy, Utah, USA)
[I provide low-cost, remote Database Administration services: www.dasages.com]