Start Oracle Database without SPFILE / PFILE.

This post will explain how can we can start an Oracle Database Instance in nomount mode, for retrival of spfile from the backup sets.

This is called as dummy instance where you don't have to define any SGA components, Oracle will take care of all the SGA related components.

So lets start, I have attached a demo just go through it.

[oracle@oracleasm2 unknown]$ echo $ORACLE_HOME
/u01/app/oracle/product/11.2.0/db_1
[oracle@oracleasm2 unknown]$ echo $ORACLE_SID

[oracle@oracleasm2 unknown]$ export ORACLE_SID=xyz
[oracle@oracleasm2 unknown]$ rlwrap rman target /

Recovery Manager: Release 11.2.0.1.0 - Production on Sun Apr 17 14:18:03 2016

Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.

connected to target database (not started)

RMAN> startup nomount force;

startup failed: ORA-01078: failure in processing system parameters
LRM-00109: could not open parameter file '/u01/app/oracle/product/11.2.0/db_1/dbs/initxyz.ora'

starting Oracle instance without parameter file for retrieval of spfile
Oracle instance started

Total System Global Area 159019008 bytes

Fixed Size 1335192 bytes
Variable Size 75497576 bytes
Database Buffers 79691776 bytes
Redo Buffers 2494464 bytes

RMAN> exit


Recovery Manager complete.
[oracle@oracleasm2 ~]$ rlwrap sqlplus / as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Sun Apr 17 14:26:22 2016

Copyright (c) 1982, 2009, Oracle. All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> show parameter spfile;

NAME                  TYPE    VALUE
------------------------------------ ----------- ------------------------------
spfile                  string