multipath - Device mapper target autoconfig

multipath [-v c verbosity] [-d] [-l|-ll|-f|-F] [-p c failover|multibus|group_by_serial|group_by_prio|group_by_node_name] [device]

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

-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

-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 ...)

-D major:minor

update only the devmap the path pointed by major:minor is in

-f

flush a multipath device map specified as parameter, if unused

-F

flush all unused multipath device maps

-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-controler 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

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

multipath was developed by Christophe Varoqui, <christophe.varoqui@free.fr> and others.