oracle@linux:~/product/10gR2/dbs> sqlplus /nolog

SQL*Plus: Release 10.2.0.1.0 - Production on Mon Aug 11 12:48:18 2008

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SQL> startup nomount
ORACLE instance started.

Total System Global Area 1090519040 bytes
Fixed Size                  1218920 bytes
Variable Size             150996632 bytes
Database Buffers          922746880 bytes
Redo Buffers               15556608 bytes
SQL> show user
USER is "SYS"
SQL> CREATE DATABASE testdb
  2     USER SYS IDENTIFIED BY cyb123
   USER SYSTEM IDENTIFIED BY cyb123
  3    4     LOGFILE GROUP 1 ('/home/oracle/oradata/testdb/redo01.log') SIZE 100M,
  5             GROUP 2 ('/home/oracle/oradata/testdb/redo02.log') SIZE 100M,
           GROUP 3 ('/home/oracle/oradata/testdb/redo03.log') SIZE 100M
   MAXLOGFILES 5
   MAXLOGMEMBERS 5
  6    7    8    9     MAXLOGHISTORY 1
   MAXDATAFILES 100
 10   11     MAXINSTANCES 1
   CHARACTER SET US7ASCII
 12   13     NATIONAL CHARACTER SET AL16UTF16
 14     DATAFILE '/home/oracle/oradata/testdb/system01.dbf' SIZE 125M REUSE
 15     EXTENT MANAGEMENT LOCAL
   SYSAUX DATAFILE '/home/oracle/oradata/testdb/sysaux01.dbf' SIZE 125M REUSE
   DEFAULT TABLESPACE tbs_1
   DEFAULT TEMPORARY TABLESPACE tempts1
 16   17   18   19        TEMPFILE '/home/oracle/oradata/testdb/temp01.dbf'
 20        SIZE 20M REUSE
   UNDO TABLESPACE undotbs
 21   22        DATAFILE '/home/oracle/oradata/testnewdb/undotbs01.dbf'
 23        SIZE 100M REUSE AUTOEXTEND ON MAXSIZE UNLIMITED;
CREATE DATABASE testdb
*
ERROR at line 1:
ORA-01501: CREATE DATABASE failed
ORA-01504: database name 'TESTDB' does not match parameter db_name 'ora01

SQL> startup nomount pfile='/home/oracle/product/10gR2/dbs/inittestdb.ora';