Sample /etc/multipath.conf file

Updated: 28 September 2026 · Applies to: AlmaLinux 9 / Rocky Linux 9

Device Mapper Multipath combines several paths to the same storage (for example two SAN or iSCSI connections) into one device, for redundancy and load balancing. This guide replaces the CentOS 7.4 sample with a current one for AlmaLinux 9 / Rocky Linux 9 (Ubuntu/Debian: package multipath-tools).

Create the configuration

dnf install device-mapper-multipath
mpathconf --enable --with_multipathd y     # writes /etc/multipath.conf and starts multipathd

Sample /etc/multipath.conf

defaults {
    user_friendly_names yes      # names like mpatha instead of the long WWID
    find_multipaths     yes      # only use multipath for devices with more than one path
}

blacklist {
    devnode "^vd[a-z]"           # example: never use multipath for local virtio disks
}

multipaths {
    multipath {
        wwid  3600a098038303053453f463045727443
        alias data01             # your own name for this LUN
    }
}

# devices { device { vendor "..." product "..." ... } }   # only if your storage vendor asks for it

Useful commands

multipath -ll                  # show multipath devices and the state of each path
multipathd show config         # the full active configuration, including built-in defaults
systemctl reload multipathd    # apply changes to multipath.conf
/lib/udev/scsi_id -g -u -d /dev/sdb    # find the WWID of a disk

Use the devices as /dev/mapper/mpatha (or your alias), never the underlying /dev/sdX paths.