ORA-01034 & ORA-27101: Shared Memory Realm Does Not Exist
ORA-27101 and ORA-01034 combined may occurs in various scenarios .One of the reason for this error is that the database is not up.
When we try to connect with oracle database or sometimes during
installation we may get this error . We may face this error in some
other scenario's too . Here are few possible scenario's ( some
scenario's are from window platform and some are from Linux platform ) .
Case 1 : When try to connect with normal user we get the error as
C:\>
sqlplus
SQL*Plus: Release 11.2.0.1.0 Production on Mon Feb 6 11:22:08 2012
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Enter user-name: scott
Enter password:
ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Process ID: 0
Session ID: 0 Serial number: 0
To solve this issue , set the ORACLE_SID and start the database using the "sys" user as sysdba and start the database ,
C:\>
set ORACLE_SID=noida
C:\>
sqlplus sys/xxxx@noida as sysdba
SQL*Plus: Release 11.2.0.1.0 Production on Mon Feb 6 11:25:13 2012
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Connected to an idle instance.
SQL>
startup
ORACLE instance started.
Total System Global Area 535662592 bytes
Fixed Size 1375792 bytes
Variable Size 331350480 bytes
Database Buffers 197132288 bytes
Redo Buffers 5804032 bytes
Database mounted.
Database opened.
Case 2 : On a
system with multiple IP addresses, when we connect with sqlplus locally
on the server (i.e. "sqlplus user/password") everything is OK, but
connecting through a TNS alias, either from the network or locally on
the server, we get the the following errors :
$ sqlplus user/password@db_alias
ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
SVR4 Error: 2: No such file or directory
We need to Manually startup the database or check whether the listener is started or not . So either connect as
$
export ORACLE_SID=noida
$
sqlplus sys/password as sysdba
SQL>
startup
or
check the status of listener if not started then start the listener as
$
lsnrctl
lsnrctl>
stop
lsnrctl>
start
lsnrctl>
exit
$
export ORACLE_SID=noida
$
sqlplus sys/password@noida as sysdba
SQL>
startup
Case 3 : Make sure while
connecting, that the ORACLE_SID and ORACLE_HOME is correctly set . There
should not be trailing trash in ORACLE_HOME path . Remove the extra
"/" from the end of ORACLE_HOME
Incorrect Home location: (ORACLE_HOME = /u01/app/oracle/product/11.2.0/)
Correct Home location : (ORACLE_HOME = /u01/app/oracle/product/9.2.0)
Once , we have correctly set the path then reload the listener and set or export ORACLE_SID before connecting as :
Linux :
$
export ORACLE_SID=noida
$
sqlplus sys/xxxx@noida as sysdba
SQL>
startup
Window :
C:\>
set ORACLE_SID=noida
C:\>
sqlplus sys/xxxx@noida as sysdba
C:\>
startup
Case 4 : Sometimes in case
of window , if event log is full , then we get this error . So delete
the event logs and try to connect again .
Case 5 : Sometimes , in case
of window , we resolve this issue by simply restart the oracle services .
so restart the window services as
start --> cmd --- > net stop oracleserviceXXXX
--- >> net start oracleservice .
Enjoy :-)
