1. Enable EPEL repository

rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

1. Install requisite packages

yum -y install binutils.x86_64 compat-libstdc++-33.x86_64 compat-libstdc++-33.i686 elfutils-libelf.x86_64 elfutils-libelf-devel.x86_64 \
               gcc.x86_64 gcc-c++.x86_64 glibc.i686 glibc.x86_64 glibc-common.x86_64 glibc-devel.i686 glibc-devel.x86_64 glibc-headers.x86_64 \
	       ksh.x86_64 libaio.i686 libaio.x86_64 libaio-devel.i686 libaio-devel.x86_64 libgcc.i686 libgcc.x86_64 libstdc++.i686 \
	       libstdc++.x86_64 libstdc++-devel.x86_64 make.x86_64 sysstat.x86_64 unixODBC.x86_64 unixODBC.i686 unixODBC-devel.i686 \
	       unixODBC-devel.x86_64 libcap.x86_64 libcap.i686 compat-libcap1.i686 compat-libcap1.x86_64 libcap-devel.x86_64 libcap-devel.i686 \
               libcap-ng.i686 libcap-ng.x86_64 libcap-ng-devel.i686 libcap-ng-devel.x86_64 smartmontools perl \
               telnet man  tigervnc-server.x86_64 xhost unzip twm xterm kernel-devel cifs-utils rpm-build pam.i686 \
               rdma ntp sg3_utils wget git pam-devel.i686

1. Install ASMlib

groupadd -g 1000 oinstall
groupadd -g 1200 dba
useradd -u 1100 -g oinstall -G dba grid11g
useradd -u 1101 -g oinstall -G dba ora11g
passwd grid11g
passwd ora11g

1. Update the system

yum -y update
reboot

Users & FS

# create Oracle SW volumegroup
pvcreate /dev/sdb
vgcreate orasw_vg /dev/sdb
lvcreate -L 9G -n dbhome_11204_lv orasw_vg
lvcreate -L 9G -n gridhome_11204_lv orasw_vg
lvcreate -L 1.5G -n orabase_11204_lv orasw_vg
mkfs.ext4 /dev/mapper/orasw_vg-dbhome_11204_lv
mkfs.ext4 /dev/mapper/orasw_vg-gridhome_11204_lv
mkfs.ext4 /dev/mapper/orasw_vg-orabase_11204_lv

# create groups and user
groupadd dba
groupadd asmdba
groupadd asmoper
useradd -g dba -G dba,asmdba,asmoper -m ora11g
echo "ora11g:broodi" | chpasswd
mkdir -p /appl/oracle/grid
mkdir /appl/oracle/db
mkdir /appl/orabase

chown -R ora11g:dba /appl
chmod -R 775 /appl

# mount FS
cat >> /etc/fstab << EOF
/dev/mapper/orasw_vg-dbhome_11204_lv /appl/oracle/db ext4 defaults 0 0
/dev/mapper/orasw_vg-gridhome_11204_lv /appl/oracle/grid ext4 defaults 0 0
/dev/mapper/orasw_vg-orabase_11204_lv /appl/orabase ext4 defaults 0 0
EOF

mount -a

chown ora11g:dba /appl/oracle/*
chown ora11g:dba /appl/orabase
chmod 775 /appl/oracle/*
chmod 775 /appl/orabase

the rest :

# configure ASM disks
cat >> /etc/udev/rules.d/90-asmdisks.rules << EOF
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/\$parent", RESULT=="217c7937a15321520", NAME="asm-disk00", OWNER="ora11g", GROUP="asmdba", MODE="0660"
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/\$parent", RESULT=="23c54da337a53e2ac", NAME="asm-disk01", OWNER="ora11g", GROUP="asmdba", MODE="0660"
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/\$parent", RESULT=="2300143730012855d", NAME="asm-disk02", OWNER="ora11g", GROUP="asmdba", MODE="0660"
EOF

# reconfigure system services
sed -i 's/enforcing/disabled/g' /etc/selinux/config
service iptables stop
service ip6tables stop
service postfix stop
chkconfig iptables off
chkconfig ip6tables off
chkconfig postfix off

# setup networking
cat >> /etc/hosts <<EOF
192.168.88.21   racdb01
192.168.88.22   racdb02

1.1.1.21 racdb01-priv
1.1.1.22 racdb02-priv

192.168.88.31   racdb01-vip
192.168.88.32   racdb02-vip

192.168.88.37   racdb-scan
192.168.88.38   racdb-scan
EOF

KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="217c7937a15321520", NAME="asm-disk00", OWNER="ora11g", GROUP="asmdba", MODE="0660"
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="23c54da337a53e2ac", NAME="asm-disk01", OWNER="ora11g", GROUP="asmdba", MODE="0660"
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="/sbin/scsi_id -g -u -d /dev/$parent", RESULT=="2300143730012855d8", NAME="asm-disk02", OWNER="ora11g", GROUP="asmdba", MODE="0660"

Alternatively we can run the following command:

#!/bin/bash
#file ~/createOracleAsmUdevRules.sh

i=1
 # ol6 / rhel6 / centos 6 
cmd="/sbin/scsi_id -g -u -d"
for disk in sdb sdc sdd sde ; do 
         cat <<EOF >> /etc/udev/rules.d/99-oracle-asmdevices.rules
KERNEL=="sd?1", BUS=="scsi", PROGRAM=="$cmd /dev/\$parent", \
 RESULT=="`$cmd /dev/$disk`", NAME="asm-disk$i", OWNER="oracle", GROUP="dba", MODE="0660"
EOF
         i=$(($i+1)) 
done

SCSI_ID doesn't return anything

If the SCSI_ID doesn't return anything there are 2 possibilities

1. You are using VMware vSphere and the settings for that are disabled (default)
2. You are using Linux 5 and you don't use the /block/sd* path

Please correct the above problems and restart the program.