MULTIPATH(8)

NAME
multipath - Device mapper target autoconfig

SYNOPSIS
multipath [-v verbosity] [-b bindings_file] [-d] [-h|-l|-ll|-f|-t|-F|-B|-c|-q|-r|-i|-a|-u|-w|-W] [-p failover|multibus|group_by_serial|group_by_prio|group_by_node_name] [device]

DESCRIPTION
multipath is used to detect and coalesce multiple paths to devices, for fail-over or performance reasons.

OPTIONS

-v  level
    verbosity, print all paths and multipaths

    0   no output

    1   print the created or updated multipath names only, for use to feed other tools like kpartx

    2 + print all info : detected paths, coalesced paths (ie multipaths) and device maps

-h  print usage text

-d  dry run, do not create or update devmaps

-l  show the current multipath topology from information fetched in sysfs and the device mapper

-ll show the current multipath topology from all available information (sysfs, the device mapper, path checkers ...)

-f  flush a multipath device map specified as parameter, if unused

-F  flush all unused multipath device maps

-t  print internal hardware table to stdout

-r  force devmap reload

-i  ignore wwids file when processing devices

-B  treat the bindings file as read only

-b  bindings_file
    set user_friendly_names bindings file location. The default is /etc/multipath/bindings

-c  check if a block device should be a path in a multipath device

-q  allow device tables with queue_if_no_path when multipathd is not running

-a  add the wwid for the specified device to the wwids file

-u  check if the device specified in the program environment should be a path in a multipath device.

-w  remove the wwid for the specified device from the wwids file

-W  reset the wwids file to only include the current multipath devices

-p policy
    force new maps to use the specified policy:

    failover
        1 path per priority group

    multibus
        all paths in 1 priority group

    group_by_serial
        1 priority group per serial

    group_by_prio
        1 priority group per priority value. Priorities are determined by callout programs specified as a global, per-controller or per-multipath option in the configuration file

    group_by_node_name
        1 priority group per target node name. Target node names are fetched in /sys/class/fc_transport/target*/node_name.

Existing maps are not modified.

device
    update only the devmap specified by device, which is either:

    •   a devmap name

    •   a path associated with the desired devmap; the path may be in one of the following formats:

        •   /dev/sdb

        •   major:minor

SEE ALSO
multipathd(8), multipath.conf(5), kpartx(8), udev(8), dmsetup(8) hotplug(8)

AUTHORS
multipath was developed by Christophe Varoqui, <christophe.varoqui@opensvc.com> and others.