When installing Oracle ASM in an Oracle Restart (standalone) configuration, Oracle Universal Installer (OUI) creates a separate server parameter file (SPFILE) and password file for the Oracle ASM instance. The ASM SPFILE is stored in a disk group during installation.
When installing Oracle ASM in a clustered Oracle ASM environment, OUI creates a single, shared SPFILE for Oracle ASM in a disk group.
When upgrading an Oracle ASM instance, if the ASM SPFILE was originally in a shared file system, then the upgraded Oracle ASM instance retains the SPFILE in the same location. If the original Oracle ASM instance used a PFILE, then after an upgrade the instance continues to use a PFILE.
You can use an SPFILE or a text-based initialization parameter file (PFILE) as the Oracle ASM instance parameter file. If you use an SPFILE in a clustered Oracle ASM environment, then you must place the SPFILE in a disk group or on a cluster file system. Oracle recommends that the Oracle ASM SPFILE is placed in a disk group. You cannot use a new alias created on an existing Oracle ASM SPFILE to start the Oracle ASM instance
If you do not use a shared Oracle Grid Infrastructure home, then the Oracle ASM instance can use a PFILE. The same rules for file name, default location, and search order that apply to database initialization parameter files also apply to Oracle ASM initialization parameter files.
When an Oracle ASM instance searches for an initialization parameter file, the search order is:
The location of the initialization parameter file specified in the Grid Plug and Play (GPnP) profile
If the location has not been set in the GPnP profile, then the search order changes to:
SPFILE in the Oracle ASM instance home
For example, the SPFILE for Oracle ASM has the following default path in the Oracle Grid Infrastructure home in a Linux environment:
$ORACLE_HOME/dbs/spfile+ASM.ora
PFILE in the Oracle ASM instance home
A PFILE or SPFILE is required if your configuration uses nondefault initialization parameters for the Oracle ASM instance.
You can administer Oracle ASM initialization parameter files with SQL*Plus, ASMCA, and ASMCMD commands. For information about the ASMCA GUI and command-line interfaces, see Managing Oracle ASM With ASMCA . For information about ASMCMD commands for managing an Oracle ASM SPFILE; such as spbackup, spcopy, and spmove; see "ASMCMD Instance Management Commands".
Oracle Database Administrator's Guide for more information about creating and maintaining initialization parameter files
Oracle Database SQL Language Reference for information about creating an SPFILE with the CREATE SPFILE SQL statement