Provided by: multipath-tools_0.7.4-2ubuntu3.2_amd64 
NAME
multipath - Device mapper target autoconfig.
SYNOPSIS
multipath [-v verbosity] [-b bindings_file] [-d] [-h|-l|-ll|-f|-t|-F|-B|-c|-C|-q|-r|-i|-a|-u|-U|-w|-W]
[-p failover|multibus|group_by_serial|group_by_prio|group_by_node_name] [-R retries] [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 Display the currently used multipathd configuration.
-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.
-C Check if a multipath device has usable paths. This can be used to test whether or not I/O on this
device is likely to succeed. The command itself doesn't attempt to do I/O on the 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.
-U Check if the device specified in the program environment is a multipath device with usable paths.
See -C.
-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 One path per priority group.
multibus All paths in one priority group.
group_by_serial
One priority group per serial number.
group_by_prio
One 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
One priority group per target node name. Target node names are fetched in
/sys/class/fc_transport/target*/node_name.
Existing maps are not modified.
-R retries
Number of times to retry flushing multipath devices that are in-use. The default is 0.
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/sdX
• major:minor
SEE ALSO
multipathd(8), multipath.conf(5), kpartx(8), udev(8), dmsetup(8), hotplug(8).
AUTHORS
multipath-tools was developed by Christophe Varoqui <christophe.varoqui@opensvc.com> and others.