I installed oracle 11g on ubuntu 14.04 and i started lister and the message is as below.

LSNRCTL for Linux: Version - Production on 10-OCT-2014 14:20:02

Copyright (c) 1991, 2011, Oracle.  All rights reserved.

Starting /u01/app/oracle/product/11.2.0/xe/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version - Production
System parameter file is /u01/app/oracle/product/11.2.0/xe/network/admin/listener.ora
Log messages written to /u01/app/oracle/diag/tnslsnr/TSDC/listener/alert/log.xml

Alias                     LISTENER
Version                   TNSLSNR for Linux: Version - Production
Start Date                10-OCT-2014 14:20:02
Uptime                    0 days 0 hr. 0 min. 0 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Default Service           XE
Listener Parameter File   /u01/app/oracle/product/11.2.0/xe/network/admin/listener.ora
Listener Log File         /u01/app/oracle/diag/tnslsnr/TSDC/listener/alert/log.xml
Listening Endpoints Summary...
Services Summary...
Service "XE" has 1 instance(s).
  Instance "XE", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

Then I started the server by oracle-xe start and it was started successfully.

When I was trying to connect to sql*plus following error was getting..

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

Please suggest me what to do with this?

  • Can you post the contents of listener.ora, $ORACLE_HOME and $ORACLE_SID? One possible cause for this error would be a trailing '/' after ORACLE_HOME in listener.ora
    – sjk
    Commented Oct 10, 2014 at 10:42
  • please do a "ps -ef|grep pmon" on your server, and make sure the database you're looking for has an active PMON process. The error you have suggests that your DB is not running. Commented Oct 10, 2014 at 14:00
  • sqlplus / as sysdba then issue command startup; to start the database.
    – mutap
    Commented Oct 11, 2014 at 19:23
  • i could't find the error.Finally i reinstalled oracle to solve the problem. Commented Oct 13, 2014 at 4:08
  • @mutap can you please write your comment in the form of an answer so I can +1. I searched for a whole day and couldn't find solution. Until I read your comment. Thanks Commented Nov 18, 2014 at 9:08

1 Answer 1


Run sqlplus / as sysdba then issue command startup; to start the database.

Also on Linux with this error, you can check first if Oracle background processes are up with ps aux | grep pmon. Pmon is process monitor, or check some other background process. If they are not running then the database is not running.

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