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I have downloaded Oracle XE 11.2.0-1.0 and installed it on a CentOS 6.3 virtual machine with 1.5GB memory and 3GB of swap.

SYS and SYSTEM set to have password 123456. I have set ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe/ and ORACLE_SID=XE.

I can connect to this database with SQL Developer with the SYSTEM user. But when I want to connect with sqlplus it says:

ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory
Process ID: 0
Session ID: 0 Serial number: 0

ps -fe | grep pmon shows this:

oracle    1164    1    0    11:26    ?    00:00:00    xe_pmon_XE

I have logged in as root user and I just type sqlplus with no arguments then it asks for user name and password.

Can anyone help?

share|improve this question
That usually means you haven't started Oracle (but the listener is running). – a_horse_with_no_name Sep 3 '12 at 6:39
@a_horse_with_no_name I can create tables, ... in the database using sql developer. – Majid Azimi Sep 3 '12 at 6:46
is there a pmon process running? what is the output of ps -fe|grep pmon? I am not familiar with sqldeveloper. what connection data do you use to connect to the system? – miracle173 Sep 3 '12 at 6:47
i misread your post. how do you connect with sqlplus? – miracle173 Sep 3 '12 at 6:48
Then your connection using SQLPlus is wrong. Please show us the connection details you use in SQL Developer and SQLPlus – a_horse_with_no_name Sep 3 '12 at 6:55
up vote 2 down vote accepted

I have removed the trailing / from ORACLE_HOME and it solved my problem.

share|improve this answer
This is the only solution that worked for me! – warl0ck Jan 29 at 14:33

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