ORA-12705: Cannot access NLS data files or invalid environment specified / ORA-01092: ORACLE instance terminated. Disconnection forced

[oraprod@dbprod ~]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.2.0 - Production on Mon Jun 16 19:27:00 2008
Copyright (c) 1982, 2005, Oracle.  All Rights Reserved.

ERROR:
ORA-12705: Cannot access NLS data files or invalid environment specified

[oraprod@dbprod 10.2.0]$ unset NLS_LANG
[oraprod@dbprod 10.2.0]$ sqlplus sys/sys as sysdba

SQL*Plus: Release 10.2.0.2.0 - Production on Mon Jun 16 16:05:42 2008

Copyright (c) 1982, 2005, Oracle.  All Rights Reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area 1073741824 bytes
Fixed Size                  1264892 bytes
Variable Size             654312196 bytes
Database Buffers          406847488 bytes
Redo Buffers               11317248 bytes
Database mounted.
ORA-01092: ORACLE instance terminated. Disconnection forced

   
Check yours alert log file

Errors in file /orahome/PROD/db/tech_st/10.2.0/admin/PROD_dbprod/udump/prod_ora_27138.trc:
ORA-12701: CREATE DATABASE character set is not known
Mon Jun 16 14:38:01 2008
Error 12701 happened during db open, shutting down database
USER: terminating instance due to error 12701
Instance terminated by USER, pid = 27138
ORA-1092 signalled during: ALTER DATABASE OPEN...
Mon Jun 16 14:48:21 2008

The above error comes after running autoconfig on database side.

Cause
-----
One of parameter NLS_LANG or ORA_NLS10 is not set correctly.

Solution
--------
check ora_nls10 path


[oraprod@dbprod udump]$ echo $ORA_NLS10
/orahome/PROD/db/tech_st/10.2.0/ocommon/nls/admin/data


Path should be (10g rel 2) ORA_NLS10="/orahome/PROD/db/tech_st/10.2.0/nls/data/9idata"
it would more appropriate to set the path in environment variable file.


[oraprod@dbprod 10.2.0]$ vi PROD_dbprod.env

#ORA_NLS10="/orahome/PROD/db/tech_st/10.2.0/ocommon/nls/admin/data"
ORA_NLS10="/orahome/PROD/db/tech_st/10.2.0/nls/data/9idata"


Save and then open the terminal again.


or you can change at shell

[oraprod@dbprod 10.2.0]$ echo $ORA_NLS10
/orahome/PROD/db/tech_st/10.2.0/ocommon/nls/admin/data
[oraprod@dbprod 10.2.0]$ ORA_NLS10=/orahome/PROD/db/tech_st/10.2.0/nls/data/9idata
[oraprod@dbprod 10.2.0]$ echo $ORA_NLS10
/orahome/PROD/db/tech_st/10.2.0/nls/data/9idata
[oraprod@dbprod 10.2.0]$ sqlplus sys/sys as sysdba

SQL*Plus: Release 10.2.0.2.0 - Production on Mon Jun 16 16:10:46 2008

Copyright (c) 1982, 2005, Oracle.  All Rights Reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area 1073741824 bytes
Fixed Size                  1264892 bytes
Variable Size             654312196 bytes
Database Buffers          406847488 bytes
Redo Buffers               11317248 bytes
Database mounted.
Database opened.