Sample configuration file for Red Hat Enterprise Linux 5

All versions of Red Hat Enterprise Linux 5 series use a DM-Multipath configuration file, but there might be slight variations in the file based on which Red Hat update you have installed. You can replace your current file with the sample file, and then change the values to ones that are appropriate for your system.

SAN boot LUNs on Red Hat Enterprise Linux 5 series and user_friendly_names parameter

You can use the sample Red Hat Enterprise Linux 5 series configuration files shown here to create your own multipath.conf file. When you create your file, keep the following in mind:

Red Hat Enterprise Linux 5 series notes	Explanation
Blacklist section	You must provide information that is specific to your system in the blacklist section. Any names shown in the sample files are examples and will not work with your system.
SAN boot LUNs and the user_friendly_names parameter	NetApp recommends that you set the user_friendly_names parameter to no. There have been reports of problems when this parameter is set to yes.
Red Hat Enterprise Linux 5 prior to Update 6	If you are using a version of Red Hat Enterprise Linux 5 series prior to update 6, check the Recommended Host Settings for Linux Host Utilities to see whether there are any parameter values specific to that version.

If you create a SAN boot LUN and the installer sets the user_friendly_names parameter to yes, you must perform the following steps:

Change the user_friendly_names parameter to no.
Make a backup of initrd-image.
Re-create the initrd-image by using the mkinitrd command.
Use the following command line: mkinitrd -f /boot/initrd-"`uname -r`".img `uname -r`
Change the root dm-multipath device name to the WWID-based device name in all the locations that refer to the device, such as /etc/fstab and /boot/grub/device.map.
For example, suppose the name of the root device is /dev/mapper/mpatha and the WWID of the device is 360a98000486e2f66426f583133796572. You must re-create the initrd-image, and then change the device name to /dev/mapper/360a98000486e2f66426f583133796572 in /etc/fstab and /boot/grub/device.map, as well as any other place that refers to the /dev/mapper/mpatha device.
Reboot the host.

The following file provides an example of the values you need to supply when your host is running Red Hat Enterprise Linux 5 with update 10, 9, 8 or update 7 and has ALUA enabled.

Note: Both Red Hat Enterprise Linux 5 update 11, 10, 9, 8 and Red Hat Enterprise Linux 5 update 7 use the same values in the DM-Multipath configuration file, so this file can apply to either version.

Remember: If you use the blacklist section, you must replace the sample information with information for your system.

defaults {
        user_friendly_names   no
        queue_without_daemon  no
        flush_on_last_del     yes
        max_fds               max
        pg_prio_calc 	      avg
}
# All data under blacklist must be specific to your system.
blacklist {
devnode "^hd[a-z]"
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^cciss.*"
} 
devices {
device {
       vendor                  "NETAPP"
       product                 "LUN"
       path_grouping_policy    group_by_prio
       features                "3 queue_if_no_path pg_init_retries 50"
       prio_callout            "/sbin/mpath_prio_alua /dev/%n"
       path_checker            tur
       path_selector           "round-robin 0"
       failback                immediate
       hardware_handler        "1 alua"
       rr_weight               uniform
       rr_min_io               128
       getuid_callout          "/sbin/scsi_id -g -u -s /block/%n"
}
}

The following file provides an example of the values you need to supply when your host is running Red Hat Enterprise Linux 5 with update 11,10, 9, 8 or update 7 and does not have ALUA enabled.

Note: Unless you are running the iSCSI protocol and Data ONTAP operating in 7-Mode, you should have ALUA enabled.

Remember: If you use the blacklist section, you must replace the sample information with information for your system.

defaults {
        user_friendly_names   no
        queue_without_daemon  no
        flush_on_last_del     yes
        max_fds               max
        pg_prio_calc 	      avg
}
# All data under blacklist must be specific to your system.
blacklist {
devnode "^hd[a-z]"
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^cciss.*"
}
devices {
device {
       vendor                  "NETAPP"
       product                 "LUN"
       path_grouping_policy    group_by_prio
       features                "3 queue_if_no_path pg_init_retries 50"
       prio_callout            "/sbin/mpath_prio_ontap /dev/%n"
       path_checker            tur
       path_selector           "round-robin 0"
       failback                immediate
       hardware_handler        "0"
       rr_weight               uniform
       rr_min_io               128
       getuid_callout          "/sbin/scsi_id -g -u -s /block/%n"
}
}

The following file provides an example of the values you need to supply when your host is running Red Hat Enterprise Linux 5 with update 6 and has ALUA enabled:

Remember: If you use the blacklist section, you must replace the sample information with information for your system.

defaults {
        user_friendly_names   no
        queue_without_daemon  no
        flush_on_last_del     yes
        max_fds               max
        pg_prio_calc 	        avg
}
# All data under blacklist must be specific to your system.
blacklist {
devnode "^hd[a-z]"
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^cciss.*"
} 
devices {
device {
       vendor                  "NETAPP"
       product                 "LUN"
       path_grouping_policy    group_by_prio
       features                "1 queue_if_no_path"
       prio_callout            "/sbin/mpath_prio_alua /dev/%n"
       path_checker            directio
       path_selector           "round-robin 0"
       failback                immediate
       hardware_handler        "1 alua"
       rr_weight               uniform
       rr_min_io               128
       getuid_callout          "/sbin/scsi_id -g -u -s /block/%n"
}
}

The following file provides an example of the values you need to supply when your host is running Red Hat Enterprise Linux 5 with update 6 and does not have ALUA enabled.

Note: Unless you are running the iSCSI protocol and Data ONTAP operating in 7-Mode, you should have ALUA enabled.

Remember: If you use the blacklist section, you must replace the sample information with information for your system.

defaults {
        user_friendly_names   no
        queue_without_daemon  no
        flush_on_last_del     yes
        max_fds               max
        pg_prio_calc 	        avg
}
# All data under blacklist must be specific to your system.
blacklist {
devnode "^hd[a-z]"
devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
devnode "^cciss.*"
}
devices {
device {
       vendor                  "NETAPP"
       product                 "LUN"
       path_grouping_policy    group_by_prio
       features                "1 queue_if_no_path"
       prio_callout            "/sbin/mpath_prio_ontap /dev/%n"
       path_checker            directio
       path_selector           "round-robin 0"
       failback                immediate
       hardware_handler        "0"
       rr_weight               uniform
       rr_min_io               128
       getuid_callout          "/sbin/scsi_id -g -u -s /block/%n"
}
}