Red Hat

mpatha (1IET     00010001) dm-2 IET,VIRTUAL-DISK
size=100M features='0' hwhandler='0' wp=rw
|-+- policy='round-robin 0' prio=1 status=active
| `- 2:0:0:1 sda 8:0    active ready running
`-+- policy='round-robin 0' prio=1 status=enabled
  `- 3:0:0:1 sdb 8:16   active ready running

# cat /etc/multipath.conf
defaults {
        user_friendly_names     yes
        udev_dir                /dev
        polling_interval        10
        path_grouping_policy    failover
        getuid_callout          "/lib/udev/scsi_id --whitelisted --device=/dev/%n"
        failback                immediate
        no_path_retry           fail
    verbosity        3
}
multipaths {
       multipath {
              wwid     1IET_____00010001
              alias     qdisk_lun
    }
}


blacklist {
}

# uname -a
Linux desktopA.home.org 2.6.32-431.el6.x86_64 #1 SMP Fri Nov 22 03:15:09 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

# ls -ld /dev/dm-5 
brw-rw----. 1 root disk 253, 5 Sep 26 15:21 /dev/dm-5
# ls -ld /dev/mapper/mpatha 
lrwxrwxrwx. 1 root root 7 Sep 26 15:21 /dev/mapper/mpatha -> ../dm-3

# cat /etc/multipath.conf
defaults {
        user_friendly_names     yes
    getuid_callout "/lib/udev/scsi_id --whitelisted --replace-whitespace --device=/dev/%n"
}
multipaths {
       multipath {
        wwid    1IET_00030001
              alias     datalun01
    }
}

blacklist {
}