Fixing the inconsistent path ordering when using friendly_names and a separate var partition on RHEL 5

cause

• RHEL 5 multipath bindings file is located in var
• /var isn't mounted before multipath is configured
• redhat does not include /var/lib/ in the initial ram disk which breaks multipath on boot

solution (work around)

dont forget to comment out vi /etc/multipath.conf

add the following lines to multipath config to set netapp specific settings

defaults {
    user_friendly_names yes
    bindings_file /etc/multipath/bindings ##changed 
    flush_on_last_del       yes
    max_fds max
    pg_prio_calc    avg
    queue_without_daemon    no
}


devices {

    device {
            vendor                  "NETAPP"
            product                 "LUN"
            path_checker            tur
            path_selector           "round-robin 0"
            getuid_callout          "/sbin/scsi_id -g -u -s /block/%n"
#           prio_callout            "/sbin/mpath_prio_ontap /dev/%n"
            prio_callout            "/sbin/mpath_prio_alua /dev/%n"
#           features                "1 queue_if_no_path"
            features                "3 queue_if_no_path pg_init_retries 50"
#           hardware_handler        "0"
            hardware_handler        "1 alua"
            path_grouping_policy    group_by_prio
            failback                immediate
            rr_weight               uniform
            rr_min_io               128
    }

}




mkdir /etc/multipath
cp /var/lib/multipath/bindings /etc/multipath/bindings
cd /boot
cp initrd*img initrd*img.multipath-bak
mkinitrd -f initrd-`uname -r`.img `uname -r`
ls -ltr  #make sure the file is correct size there seems to be a bug where it intermittently creates a initrd of half the size