[oracle@11g dbs]$ pwd
/home/oracle/app/oracle/product/11.2.0/dbhome_1/dbs
[oracle@11g dbs]$ ll
total 24
-rw-rw----. 1 oracle oinstall 1544 Mar 11 13:46 hc_orcl.dat
-rw-r--r--. 1 oracle oinstall 2851 May 15  2009 init.ora
-rw-r-----. 1 oracle oinstall  658 Feb 16 05:17 initorcl.ora
-rw-r-----. 1 oracle oinstall   24 Feb 16 05:17 lkORCL
-rw-r-----. 1 oracle oinstall 1536 Feb 16 05:17 orapworcl
-rw-r-----. 1 oracle oinstall 3584 Mar 11 14:19 spfileorcl.ora


[oracle@11g dbs]$ rm -rf *
total 0


[oracle@11g dbs]$ orapwd file=/home/oracle/app/oracle/product/11.2.0/dbhome_1/dbs/orapworcl password=oracle
SQL> create pfile from memory;


File created.
[oracle@11g dbs]$ ll
-rw-rw----. 1 oracle oinstall 1544 Mar 11 16:55 hc_orcl.dat
-rw-r--r--. 1 oracle oinstall 5562 Mar 11 16:44 initorcl.ora
-rw-r-----. 1 oracle oinstall   24 Mar 11 16:55 lkORCL
-rw-r-----. 1 oracle oinstall 1536 Mar 11 16:38 orapworcl


SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup;
ORACLE instance started.


Total System Global Area  835104768 bytes
Fixed Size    2217952 bytes
Variable Size  520095776 bytes
Database Buffers  310378496 bytes
Redo Buffers    2412544 bytes
Database mounted.
Database opened.