To create asm on a node:

As root create th css service:
$ORACLE_HOME/bin/localconfig add

As oracle:

dbca -silent -configureASM -recoveryGroupRedundancy EXTERNAL -responseFile asm_dbca.rsp

ASM_DBCA.RSP FILE
=============
##############################################################################
##                                                                          ##
##                            DBCA response file                            ##
##                            ——————                            ##
## Copyright   1998, 2004, Oracle Corporation. All Rights Reserved.         ##
##                                                                          ##
## Specify values for the variables listed below to customize Oracle        ##
## Database Configuration installation.                                     ##
##                                                                          ##
## Each variable is associated with a comment. The comment identifies the   ##
## variable type.                                                           ##
##                                                                          ##
## Please specify the values in the following format :                      ##
##          Type       :  Example                                           ##
##          String     :  “”                                         ##
##          Boolean    :  True or False                                     ##
##          Number     :                                     ##
##          StringList :  {“”,””}                           ##
##                                                                          ##
## Examples :                                                               ##
##     1. dbca -progress_only -responseFile                  ##
##        Display a progress bar depicitng progress of database creation    ##
##        process.                                                          ##
##                                                                          ##
##     2. dbca -silent -responseFile                         ##
##        Creates database silently. No user interface is displayed.        ##
##                                                                          ##
##     3. dbca -silent -createDatabase -cloneTemplate                       ##
##                       -responseFile                       ##
##        Creates database silently with clone template. The template in    ##
##        reponsefile is a clone template.                                  ##
##                                                                          ##
##     4. dbca -silent -deleteDatabase -responseFile         ##
##        Deletes database silently.                                        ##
##############################################################################

#—————————————————————————–
# GENERAL section is required for all types of database creations.
#—————————————————————————–
[GENERAL]

#—————————————————————————–
# Name          : RESPONSEFILE_VERSION
# Datatype      : String
# Description   : Version of the database to create
# Valid values  : “10.0.0”
# Default value : None
# Mandatory     : Yes
#—————————————————————————–
RESPONSEFILE_VERSION = “10.0.0”

#—————————————————————————–
# Name          : OPERATION_TYPE
# Datatype      : String
# Description   : Type of operation
# Valid values  : “createDatabase” \ “createTemplateFromDB” \ “createCloneTemplate” \ “deleteDatabase” \ “configureDatabase” \ “configureASM” \ “addInstance” (RAC-only) \ “deleteInstance” (RAC-only)
# Default value : None
# Mandatory     : Yes
#—————————————————————————–
OPERATION_TYPE = “configureASM”

#———————–*** End of GENERAL section ***————————

#—————————————————————————–
# CONFIGUREASM section is used when OPERATION_TYPE is defined as “configureASM”.
#—————————————————————————–
[CONFIGUREASM]
#—————————————————————————–
# Name          : DISKLIST
# Datatype      : String
# Description   : Comma seperated list of OS disk paths to be used (eg. /dev/rdsk/disk1,/dev/rdsk/disk2)
# Default value : None
# Mandatory     : No (YES to create new diskgroup or add disks to existing diskgroup)
#—————————————————————————–
DISKLIST=/dev/oracle/asmdisk1,/dev/oracle/asmdisk2,/dev/oracle/asmdisk3

#—————————————————————————–
# Name          : NODELIST
# Datatype      : String
# Description   : Comma-separated list of cluster nodes
# Valid values  : Cluster node names
# Default value : None
# Mandatory     : No (YES for RAC)
#—————————————————————————–
#NODELIST=

#—————————————————————————–
# Name          : DISKGROUPNAME
# Datatype      : String
# Description   : Specifies the disk group name for the storage
# Default value : DATA
# Mandatory     : No
#—————————————————————————–
DISKGROUPNAME=DATA

#—————————————————————————–
# Name          : REDUNDANCY
# Datatype      : String
# Description   : Specifies the redundancy level for the diskgroup
# Valid values  : HIGH/NORMAL/EXTRENAL
# Default value : NORMAL
# Mandatory     : No
#—————————————————————————–
REDUNDANCY=EXTERNAL

#—————————————————————————–
# Name          : DISKSTRING
# Datatype      : String
# Description   : Specifies disk discovery path for ASM
# Default value : OS specific, eg. /dev/rdsk/* on Solaris
# Mandatory     : No
#—————————————————————————–
DISKSTRING=”/dev/oracle/asm*”

#—————————————————————————–
# Name          : ASM_SYS_PASSWORD
# Datatype      : String
# Description   : Specifies password for ASM instance to be created
# Default value : None
# Mandatory     : No
#—————————————————————————–
ASM_SYS_PASSWORD=”password”

#—————————————————————————–
# Name          : RECOVERYDISKLIST
# Datatype      : String
# Description   : Comma seperated list of OS disk paths to be used (eg. /dev/rdsk/disk1,/dev/rdsk/disk2)
# Default value : None
# Mandatory     : No
#—————————————————————————–
RECOVERYDISKLIST=/dev/oracle/asmdisk4,/dev/oracle/asmdisk5

#—————————————————————————–
# Name          : RECOVERYGROUPNAME
# Datatype      : String
# Description   : Specifies the disk group name for the recovery area
# Default value : RECOVERY
# Mandatory     : No
#—————————————————————————–
RECOVERYGROUPNAME=FLA

#—————————————————————————–
# Name          : RECOVERYREDUNDANCY
# Datatype      : String
# Description   : Specifies the redundancy level for the recovery diskgroup
# Valid values  : HIGH/NORMAL/EXTRENAL
# Default value : NORMAL
# Mandatory     : No
RECOVERYREDUNDANCY=EXTERNAL

#———————–*** End of CONFIGUREDISKGROUPS section ***————————
-bash-4.0$