TIP #12: Can not use TNS to login to database.

When I tried to connect to database via TNS, I got the following error :


ERROR - DBPrereq DBConection error
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
IBM AIX RISC System/6000 Error: 2: No such file or directory


However, database was available and was accessible from sqlplus in the box without using tnsnames.
TNS entry in tnsnames.ora was pinggable (tnsping for this entry was OK).
Environment settings were fine.

The problem was because of spare / in Oracle_home in listener.ora.

Wrong listener.ora
====================
SID_LIST_LISTENER_DASDBM =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /o029/home/metaAS10g/product/10.2.0.2/)
(PROGRAM = extproc)
)
(SID_DESC =
((GLOBAL_DBNAME = dasdbm.isc.upenn.edu)
(SID_NAME = dasdbm)
(ORACLE_HOME = /o029/home/metaAS10g/product/10.2.0.2/)
)
)

Correct listener.ora
====================
SID_LIST_LISTENER_DASDBM =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = /o029/home/metaAS10g/product/10.2.0.2)
(PROGRAM = extproc)
)
(SID_DESC =
((GLOBAL_DBNAME = dasdbm.isc.upenn.edu)
(SID_NAME = dasdbm)
(ORACLE_HOME = /o029/home/metaAS10g/product/10.2.0.2)
)
)