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)