MULTIPATH(8)

NAME
multipath - Device mapper target autoconfig

SYNOPSIS
multipath [-v verbosity] [-d] [-h|-l|-ll|-f|-t|-F-B] [-p failover|multibus|group_by_serial|group_by_prio|group_by_node_name] [device]

DESCRIPTION
multipath is used to detect multiple paths to devices for fail-over or performance reasons and coalesces them

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

-B  treat the bindings file as read only

-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 the path pointed by device is in. device is in the /dev/sdb (as shown by udev in the $DEVNAME variable) or major:minor format. device may alternatively be a multipath mapname

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.