ASM 11gR2 Installation & Configuration (Role Separation).
Before the database creation of an 11.2.0.X.X, 11.1.0.X.X or 10.2.0.X.X database using ASM 11.2.0.X.X (as storage option), then you need to set the ASM GID to the oracle kernel (<10.2, 11.1 or 11.2 RDBMS Oracle Home> /bin/oracle executable), this needs to be set before you execute the DBCA.