I executed the following command on both nodes as root user:
rpm -Uvh oracleasm*
Then I need to configure the ASM library, with the following command:
Type oracle and oinstall as user and group name that own the driver interface; type y to configure starting ASM library on boot and again y to scan ASM disks on boot.
Execute the same previous step on second node.
From one node only, I used the following command to create TWO disk group pointing to my "PowerPath" devices:
/etc/init.d/oracleasm createdisk DG_DATA_DWH /dev/emcpowere1
/etc/init.d/oracleasm createdisk DG_FRA_DWH /dev/emcpowerf1
Verify the cluster is configured correctly for a "Grid" creation, running as oracle user, only from one node, the following command:
./runcluvfy.sh stage -pre crsinst -n nov2210,nov2211 -verbose