NAME

       multipath - Device mapper target autoconfig

SYNOPSIS

       multipath             [-v verbosity]            [-d]            [-h|-l|-ll|-f|-F|-w|-W|-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

       -B     treat the bindings file as read only

       -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 maps to 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.

       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

       udev(8), dmsetup(8) hotplug(8)

AUTHORS

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

                                            July 2006                                MULTIPATH(8)