[oracle@jumper eygle]$ sqlplus "/ as sysdba" SQL*Plus: Release 9.2.0.4.0 - Production on Sun Aug 20 01:22:50 2006 Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved. Connected to an idle instance. SQL> startup mount ORACLE instance started. Total System Global Area  252777592 bytes Fixed Size                   451704 bytes Variable Size             134217728 bytes Database Buffers          117440512 bytes Redo Buffers                 667648 bytes Database mounted. SQL> alter database open; alter database open * ERROR at line 1: ORA-01157: cannot identify/lock data file 3 - see DBWR trace file ORA-01110: data file 3: '/opt/oracle/oradata/eygle/eygle02.dbf' SQL> alter database create datafile 3 as '/opt/oracle/oradata/eygle/eygle02.dbf'; Database altered. SQL> select name from v$datafile; NAME /opt/oracle/oradata/eygle/system01.dbf /opt/oracle/oradata/eygle/undotbs01.dbf /opt/oracle/oradata/eygle/eygle02.dbf /opt/oracle/oradata/eygle/eygle01.dbf SQL> alter database open; alter database open * ERROR at line 1: ORA-01113: file 3 needs media recovery ORA-01110: data file 3: '/opt/oracle/oradata/eygle/eygle02.dbf' SQL> recover datafile 3; Media recovery complete. SQL> alter database open; Database altered. SQL>