[root@db11g ~]# modprobe dm-multipath
[root@db11g ~]# modprobe dm-round-robin
[root@db11g ~]# chkconfig multipathd start
[root@db11g ~]# chkconfig multipathd on
[root@db11g ~]# /etc/init.d/multipathd start
Starting multipathd daemon: [  OK  ]
[root@db11g ~]# ps -ef|grep multipathd
root      3084     1  0 13:16          00:00:00 /sbin/multipathd
root      3186  2877  0 13:16 pts/0    00:00:00 grep multipathd
[root@db11g ~]# multipath -F
[root@db11g ~]# multipath -v2
Jan 15 13:17:40 | SATA_VBOX_HARDDISK_VBa64c2685-cc2f3dd0_: ignoring map
create: datadisk (SATA_VBOX_HARDDISK_VB3c0bb909-10aab3a0_) undef ATA,VBOX HARDDISK
size=16G features='0' hwhandler='0' wp=undef
`-+- policy='round-robin 0' prio=1 status=undef
  `- 1:0:0:0 sdb 8:16 undef ready running
create: fradisk (SATA_VBOX_HARDDISK_VB3edd7dc1-fd831bf4_) undef ATA,VBOX HARDDISK
size=10G features='0' hwhandler='0' wp=undef
`-+- policy='round-robin 0' prio=1 status=undef
  `- 2:0:0:0 sdc 8:32 undef ready running
[root@db11g ~]# 
[root@db11g ~]# multipath -ll
fradisk (SATA_VBOX_HARDDISK_VB3edd7dc1-fd831bf4_) dm-3 ATA,VBOX HARDDISK
size=10G features='0' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=1 status=active
  `- 2:0:0:0 sdc 8:32 active ready running
datadisk (SATA_VBOX_HARDDISK_VB3c0bb909-10aab3a0_) dm-2 ATA,VBOX HARDDISK
size=16G features='0' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=1 status=active
  `- 1:0:0:0 sdb 8:16 active ready running

[root@db11g ~]# ll /dev/mapper/*disk
brw-rw---- 1 grid asmadmin 252, 2 Jan 15 13:17 /dev/mapper/datadisk
brw-rw---- 1 grid asmadmin 252, 3 Jan 15 13:17 /dev/mapper/fradisk