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.
July 2006 MULTIPATH(8)
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